Sen. John McCain (R-Ariz.) said after visiting Baghdad last week that President Bush needs to level with the public about the need for more U.S. troops as well as dramatically more spending to make postwar Iraq peaceful enough for democracy to unfold.

McCain said that when he returns from the Middle East he plans to mount a heavy campaign on the issue in meetings with national security adviser Condoleezza Rice and other White House officials and during hearings of the Senate Armed Services Committee.

"We need to tell the American people directly, and I think they'll support it," McCain said from Islamabad, Pakistan. "We must win this conflict. We need a lot more military, and I'm convinced we need to spend a lot more money."

When Bush returns next weekend after a month at his ranch in Texas, one of the first political firestorms he will confront is a broad effort by Democrats on Capitol Hill and on the presidential campaign trail to convince the public that the administration's plans for postwar Iraq need rapid revision.

Sen. Joseph R. Biden Jr. (D-Del.), ranking minority member on the Foreign Relations Committee, said last week that the administration had "vastly underestimated" the policing and the work on Iraq's infrastructure that would be needed.

Defense Secretary Donald H. Rumsfeld said commanders have assured him that the level of U.S. troops in Iraq is adequate. Secretary of State Colin L. Powell asked the United Nations to encourage members to send more troops to Iraq as part of a U.S.-led coalition, and Bush said he expects more foreign troops to arrive in Iraq.

Aides said Bush plans to ask for more funds for Iraq in a supplemental budget request later this year. He has refused to give any range for what might be needed.

Joshua B. Bolten, director of the Office of Management and Budget, said Friday during a visit to The Washington Post that the amount will depend on the flow of oil, the security situation and the level of international contributions.

"I think the president will be comfortable coming forward with his proposal when he feels confident enough in the numbers that we feel we can give it a good justification," Bolten said. "We thought the only responsible thing to do was wait until we had a clearer picture of what the answers to those questions would be."

The skeptics' case has been bolstered by the continuing casualties among U.S. troops and by the administration's admission -- after the bombing Tuesday of U.N. headquarters in Baghdad -- that foreign-fed terrorism has become a grave threat in Iraq.

McCain, who is leading a bipartisan House and Senate delegation throughout the Middle East, said Friday that he estimates the United States needs to add $13 billion to $15 billion for reconstruction alone, "as quick as we can spend it." He said the failure to restore basic services more widely could lead to more violence.

"When it's 125 degrees and people don't have electricity and water, they get very unhappy," he said. "Time is not on our side."

A Newsweek poll released yesterday found that 60 percent of respondents thought the United States was spending too much in Iraq and should scale back, and that 69 percent were concerned the United States would be bogged down for many years in Iraq without making much progress. The telephone poll of 1,011 adults was conducted Thursday and Friday, after Tuesday's bombing of the U.N. offices, and had a margin of error of plus or minus 3 percentage points.

Sen. John McCain (R-Ariz.) right, talks with U.S. soldiers in Baghdad during his tour of the Middle East. He said the United States needs to put $13 billion to $15 billion into Iraq to restore basic services and reconstruct the country.