Iraq has rejected Iran's attempt to negotiate an end to hostilities in the Persian Gulf, Iranian and Iraqi spokesmen indicated yesterday, as Defense Secretary Richard B. Cheney arrived home to report to President Bush on the prospects for ground action against Iraqi forces occupying Kuwait.

Iraqi Deputy Prime Minister Saadoun Hammadi, who traveled to Tehran Saturday to bring Iraq's reply to a peace initiative launched last week by Iranian President Ali Akbar Hashemi Rafsanjani, said in Amman, Jordan, yesterday: "We told the Iranians that the current issue is not the issue of Kuwait, but that of the American, colonialist and Zionist aggression to destroy Iraq and control the region." Peace can be restored "after Muslims unite and drive out this aggression," Hammadi said.

Cheney was not carrying a specific recommendation to Bush on when a ground war should begin, according to U.S. military officials. "There is no date," said one official with direct knowledge of the officials' weekend consultations in Saudi Arabia. "That's the truth."

But after nine hours of meetings with the U.S. commander, Gen. H. Norman Schwarzkopf, and his staff, Cheney began to say "when," not "if," in his discussions of land and amphibious battle. However, several officers hinted that a few weeks' delay would give allied pilots a chance to further weaken Iraqi defenses.

Cheney, who on Friday lauded the first phases of Operation Desert Storm as "the most successful air campaign in the history of the world," said on his return flight to Washington that some Iraqi divisions had lost "as much as 40 percent" of their combat effectiveness.

Cheney and Gen. Colin L. Powell, chairman of the Joint Chiefs of Staff, who traveled with Cheney to Saudi Arabia, made no statement on arrival at Andrews Air Force Base last night. They are scheduled to report on their trip in a meeting with Bush today.

As the two top U.S. defense leaders were flying home, Iraqi President Saddam Hussein made his first nationwide broadcast since shortly after the Persian Gulf War began Jan. 17. Saddam congratulated Iraqis for their "steadfastness, faith and light" in withstanding the allied "warplanes of shame." Valor on the home front, the Iraqi leader added, was inspiring the huge Iraqi army entrenched at the southern front.

In Washington, the broadcast drew a rebuke from Bush as he returned to the White House from Camp David. "I didn't hear him say anything about him getting out of Kuwait," Bush said. "Of course, that's what the whole world is wanting to hear."

Even as Iraq appeared to reject the Iranian peace initiative Soviet President Mikhail Gorbachev said he would send a special envoy to Baghdad with what was described in Moscow as "an offer to cease fire." Gorbachev on Saturday warned that the allied aerial destruction of Iraq threatens to exceed the mandate in the United Nations resolutions calling for a complete Iraqi withdrawal from Kuwait.

Secretary of State James A. Baker III welcomed the Soviet mission, while playing down any suggestion that Soviet support for the allies is ebbing. "The Soviet Union gave us prior notice of this {Gorbachev} statement," Baker said on CBS's "Face the Nation." British Foreign Secretary Douglas Hurd, on a visit to Saudi Arabia, echoed Baker's assessment and said that the bombardment of Iraq is "directed to weakening the military machine in Kuwait."

Gorbachev's senior military adviser, Marshal Sergei Akhromeyev, said Moscow is concerned because "the longer the war drags on, more and more civilians are getting killed." Allied "strikes have been delivered against the communications centers, which are in populated areas in Iraq," Akhromeyev said on ABC's "This Week With David Brinkley." He said, "These strikes have to be prevented."

Akhromeyev, who as chief of staff of the Soviet military worked closely with Baghdad during Iraq's eight-year war against Iran, also predicted that "the Iraqi armed forces will be routed," but not before offering "stiff resistance" that "will last for a considerable length of time."

A return of fair weather over much of Iraq and Kuwait permitted allied aircraft to launch 2,800 sorties yesterday, including 650 bombing runs against greater Kuwait and 200 missions against the Republican Guard. For the first time in a week, an American plane was reported lost on a combat strike. The Marine AV-8B Harrier went down over southern Kuwait. Search-and-rescue teams hunted for the missing Marine pilot.

In limited naval and ground action, Navy A-6 attack jets struck two Iraqi patrol boats and "destroyed both" in the northern Persian Gulf, Brig. Gen. Richard Neal told reporters in Riyadh, Saudi Arabia. An Army Apache helicopter destroyed a building in Kuwait believed to be a headquarters or communications outpost.

Forty-two more Iraqis surrendered to U.S. forces yesterday, including 17 "line crossers" who defected without their weapons, Neal said. Thirty-three additional Iraqis surrendered to Saudi and Egyptian troops yesterday. Some defectors have reported that outposts manned by "two or three" members of the elite Republican Guard have been established on the "main avenues of approach, watching for deserters coming south," the general added. These may be part of what the top Saudi commander last week referred to as "execution battalions" established to punish defectors, Neal said.

Among the bombers participating in the weekend raids were U.S. B-52s making their first sorties from the English air base at Fairford, 75 miles west of London. Five of the huge bombers returned to the base before dawn yesterday after an apparent strike mission.

British Tornadoes continued their campaign against Iraqi bridges, striking another four spans yesterday including two pontoon bridges recently erected to keep supplies flowing to the Republican Guard. Other aircraft destroyed two hardened aircraft shelters in central Iraq, two Silkworm anti-ship missile sites in Kuwait and an artillery manufacturing plant, according to Group Capt. Niall Irving. About half of the British raids over greater Kuwait encountered antiaircraft fire. Size of Iraqi Force Noted

Both directly and obliquely, U.S. military officials appeared to suggest yesterday that the air campaign against Iraq should continue for a while before any ground offensive begins. In a news conference in Riyadh shortly before leaving Saudi Arabia yesterday, Cheney noted "the enormous size of the Iraqi military establishment, the size of the army, the enormous number of tanks, the hardened aircraft shelters, the redundant communication systems." Although "I don't think it's the fourth-largest army {in the world} anymore," Cheney said, "a very significant part" of the force still survives.

Asked whether the allied air strikes are approaching a point of diminishing returns, the secretary replied, "I think that the capability of U.S. air power to do damage to Saddam Hussein's forces is still considerable."

On the flight back to Washington last night, Cheney added, "Nobody wants to rush prematurely into the next phase of the campaign. . . . I think we have to be cautious not to underestimate {Saddam's} remaining capabilities." The allies "might get lucky. He could collapse. He could decide to withdraw. He could surrender. . . . But we can't plan on that," the secretary added.

Neal, the Marine general who on Saturday disclosed that about 20 percent of Iraq's armor and artillery forces has been destroyed, yesterday stressed the opportunities still available to pilots hunting for enemy targets. "From my point of view, right now, it's a target-rich environment," Neal told reporters. "It looks like it's going to be a target-rich environment for a while."

Irving of the Royal Air Force gave some sense of the magnitude of the task still facing allied bombers when he noted that each Iraqi artillery fortification requires a separate bombing mission. "One airplane takes one artillery piece," Irving said, "and when he's got 4,000 of them, it's going to take a while to wear him down." Congressional Views

Several congressional leaders yesterday stressed the benefits of continuing the air attacks. "I think we ought to continue what we're doing. We're being very successful in the air," said Senate Minority Leader Robert J. Dole (R-Kan.). "We've got some time. We've got two, three, four weeks in my view before we do anything else."

Dole also cautioned that the political consensus that supports the air war could break down in intense ground fighting. "I don't think Americans are ready for war, period. . . . If there's a ground offensive and there are thousands of casualties, support for this effort is going to drop, I think, rather sharply."

Dole also said "there's a bit of truth" in Gorbachev's charge that the allied coalition threatens to go beyond the U.N. resolutions to oust Iraq from Kuwait to, in effect, destroy Iraq militarily. But the Kansas Republican said the bombing was justified to minimize American casualties.

Overnight raids in Baghdad damaged several government buildings, including the Ministry of Industry and Military Industrialization, according to Associated Press correspondent Salah Nasrawi. The raiders also targeted two major bridges over the Tigris River, reportedly demolishing the July 14 Bridge and damaging the Martyrs' Bridge.

Baghdad Radio fired back with another scathing denunciation of Bush and a vow that when the ground war begins, American "heads will be crushed and thousands of plastic coffins will be sent to the United States."

Despite the defiant broadcast, Western correspondents arriving in Jordan after a week in besieged Iraq yesterday recounted "the disappointment and bitterness of many Iraqis with a government whose declared aim was to turn Iraq into a shining example of progress in the Middle East," as Reuter reporter Bernd Debusmann put it.

Debusmann echoed other correspondents' conclusions in asserting that "this is not a popular war and a fast-growing number of Iraqis resent the huge gap between reality and government statements that exude confidence, defiance and predictions of victory. And the conventional wisdom that people under bombing attack rally behind their leader does not appear to apply in Iraq." The Reuter reporter quoted a businessman in the southern town of Diwaniyah as saying, "The Americans inflicted more damage on our country in the first two hours of the war than the Iranians did in eight years. Where will it end?"

Hammadi, the Iraqi deputy prime minister, said at his news conference in Amman that Iraq would be willing to enter into talks on the gulf war after a withdrawal of U.S. forces. But he insisted that Kuwait is not the issue in the war and that Iraq is prepared to fight on.

Rafsanjani acknowledged yesterday that Iraq's response to his initiative had not been "up to the level" of Tehran's expectations but that "all doors have not been closed." Iranian Foreign Minister Ali Akbar Velayati expressed similar views in a television interview, saying "I think it needs more time and more effort."

Meanwhile Jordan's King Hussein said on "This Week With David Brinkley" that he was "hurt" that his "appeal for peace, has been so misunderstood and misinterpreted." Hussein angered Bush last week by alleging that the war is being waged against all Arabs and Muslims as part of a U.S. bid to dominate the Middle East. In an apparent effort to repair relations, the king reiterated his condemnation of Iraq's occupation of Kuwait as, he said, he had done "zillions of times before."

Staff writers Nora Boustany in Jordan and Edward Cody in Saudi Arabia contributed to this report.