DAMASCUS, SYRIA, SEPT. 13 -- Secretary of State James A. Baker III told the Soviet leadership today that the United States is considering asking for new U.N. sanctions to plug leaks in the global economic embargo against Iraq, and Baker responded sharply to Iran's call for a "holy war" against American troops in the Persian Gulf.

Baker told Soviet Foreign Minister Eduard Shevardnadze that the United States may seek U.N. approval for additional sanctions such as an air interdiction effort to prevent supplies from being flown into Iraq, according to State Department spokesman Margaret Tutwiler. He also discussed possible sanctions against nations that seek to break the embargo, she said.

Baker arrived in Damascus tonight for the first meeting of a high-level U.S. official in more than two years with Syrian President Hafez Assad, whom the United States has sought to isolate because of his past support for terrorism.

But Assad has committed 3,000 Syrian troops to the multinational force in Saudi Arabia and another 1,000 to the United Arab Emirates and U.S. officials said a major item for discussions here is Syria sending additional troops and tanks to join those already deployed with the multinational force. A Western diplomat said today that Syria is prepared to send a 10,000-man armored division with 300 tanks to Saudi Arabia, if asked.

Meeting in Moscow this morning with Shevardnadze and later with President Mikhail Gorbachev, Baker did not ask the Soviets to approve any new measures on the gulf crisis, Tutwiler said, but he "said he was thinking along these lines and there would be additional areas" in the future. At last weekend's Helsinki summit, Gorbachev and President Bush pledged to take additional steps if the sanctions already in place do not achieve their goal of forcing Iraq to relinquish Kuwait.

Gorbachev reiterated to reporters today before the meeting with Baker that the Soviet Union will not commit troops to the multinational effort. "I hope that there is no need and that there will be no need," he said.

After the meeting, Baker said that the United States believes the embargo is "holding" and "we are watching it closely." There have been reports that Libya and North Korea might be trying to break the embargo by flying supplies into Iraq. According to officials traveling with Baker, the United States has been told by other Arab leaders that the embargo is largely intact and the officials said they do not have evidence that Iran has allowed any serious violation of the embargo.

Iran has publicly supported the embargo against Baghdad and Baker noted today that Iran has "repeatedly made it clear that it will abide by the embargo and go along with the will of the United Nations."

On Wednesday, Iran's spiritual leader, Ayatollah Ali Khamenei, said an Islamic "holy war" is justified against U.S. troops deployed in Saudi Arabia. It was the first time since Iraq invaded Kuwait Aug. 2 that a member of Iran's leadership had issued such a denunciation of the U.S. presence there. But some analysts and officials say the comments reflect a continuing split in Iran's leadership between hard-liners such as Khamenei and the relatively pragmatic President Ali Akbar Hashemi Rafsanjani.

Baker said Khamenei's comments "are obviously of deep concern." He added, "We are not indifferent to threats against our forces, which are there as part of a multinational presence that includes Moslem and Arab nations. The Iranians know that we have been invited in to deter an Iraqi attack and provide for the defense of Saudi Arabia."

The gulf crisis appeared to dominate Baker's meeting at the Kremlin today with Shevardnadze and Gorbachev. Officials said Gorbachev encouraged Baker to go to Syria, which has had close ties with Moscow.

Baker has said his trip is part of a diplomatic effort to isolate Iraqi President Saddam Hussein by bringing his foes into the multinational force, even though Syria and the United States have not had good relations. Syria is one of Iran's closest allies in the region and both nations have long been at odds with Iraq. In 1989, Iraq poured a large amount of weapons into Lebanon to help Christian militia there battle Syrian-backed forces.

Syria is also on the State Department's list of nations that sponsor terrorism and Baker said last week he would raise the issue with Assad but does not believe "differences" over terrorism should stop him from meeting the Syrian president.

Baker is the first high-level U.S. official to meet with Assad since before the Pan Am 103 bombing in December 1988. The perpetrators of that attack have been linked to Syria and Iran. Baker has displayed an unusual sensitivity about this visit; aides today gave reporters a long list of previous trips by American secretaries of state to Damascus in an effort to suggest this trip is not that unusual.

On other matters, a senior official said Baker and Gorbachev had only a brief discussion of arms control and no major progress was made on the Strategic Arms Reduction Treaty. Although Bush and Gorbachev have said they would like to complete the treaty this year, the talks have been virtually stalled.

Gorbachev told reporters that the Soviet Union will be making new proposals on troop levels in Europe. However, a senior State Department official said no new proposals came in today's meetings. Shevardnadze recently told Baker that the U.S.-Soviet troop levels agreed to in Ottawa earlier this year have been overtaken by events -- primarily Moscow's decision to pull its troops out of Germany. The Ottawa levels envisioned 195,000 U.S. troops in the "central zone" of Europe, primarily Germany. But now that the Soviets are exiting, they do not want to lock these U.S. levels into a treaty.

Shevardnadze's attitude toward the Ottawa levels, the official said, is to "let it go away." The official said Shevardnadze has explicitly told the United States that the Soviet Union does not want to include any manpower limit in the treaty on conventional forces in Europe now being negotiated.

Recently, a Soviet negotiator suggested a U.S. limit of 70,000 to 80,000 troops. However, the State Department official said Shevardnadze has never brought this proposal to senior U.S. officials in recent meetings. The official speculated that the proposal was generated by the Soviet foreign affairs bureaucracy and had not won the approval of the top political leadership. But the official acknowledged that at some point Moscow would seek a commitment from the United States to lower troop levels.

"Do they want to see lower U.S. levels? Unquestionably," the official said. But "the political leadership is not taking up" the idea at this time, he added. "Shevardnadze has had plenty of opportunity to raise it and he has made quite clear he does not want to raise it now."

Gorbachev said he and Bush would meet again in December "if our ministers do not spoil that," referring to incomplete negotiations on strategic arms that the United States has said must be finished before another U.S.-Soviet summit. "We have instructed them {the ministers} to do things, and they must do them," Gorbachev said. "A lot of work has to be done first."

Officials also said Gorbachev today handed Baker a written response to proposals the United States made last summer for technical economic aid to the Soviet Union. The U.S. proposals included suggestions for a banking system, ways to improve distribution of goods, and housing. The officials gave no details on Gorbachev's response.