TOKYO - Any hope Defense Secretary Donald H. Rumsfeld had of being greeted in Japan with government assurances of a speedy dispatch of troops to Iraq were dashed even before he arrived today.

Rumsfeld was whisked directly from the airport to an evening meeting with Prime Minister Junichiro Koizumi, whose government announced a day earlier while Rumsfeld was visiting Guam that it almost certainly will delay sending a contingent of non-combat troops until sometime next year.

Japan is one of America's most steadfast allies - arguably the most important in Asia - and it has pledged billions of dollars in financial aid for Iraq's reconstruction. The Bush administration had hoped the Japanese also would send troops before the end of the year. But after Wednesday's deadly attack on the Italian compound in south-central Iraq, Chief Cabinet Secretary Yasuo Fukuda backed off, saying the security situation in Iraq is not yet stable enough.

After Rumsfeld's 45-minute meeting with Koizumi, a Rumsfeld aide who briefed reporters on condition he not be identified said the subject of Japanese troops in Iraq was raised by neither man.

The aide said Koizumi told Rumsfeld he admired the Bush administration's determination to stay the course in Iraq and that Japan will remain a strong supporter. Rumsfeld thanked the Tokyo government for its pledge of $1.5 billion in grants for 2004 and an additional $3.5 billion in loans over the following three years. Koizumi did not mention plans for further steps to help.

Koizumi also stressed to Rumsfeld the importance of making people in Iraq, in the Gulf region and around the world understand the importance of the cause of stabilizing and rebuilding Iraq, "and he wanted to think of ways that it could be better understood," the aide said. He and another senior U.S. official present at the meeting said they did not take this as a criticism from Koizumi.

In an interview with reporters flying with him to Tokyo, Rumsfeld showed no sign of disappointment at Japan's decision and even suggested that the U.S.-led coalition in Iraq is gaining strength.

He said he was impressed by Italy's stated determination to remain in Iraq, even after losing 14 people in the attack at Nasiriya. The Italians indicated they may send replacement forces, he said.

"So the signal that's been sent is quite the contrary" to any suggestion that the coalition is in trouble in Iraq, Rumsfeld said, noting that 32 countries have troops on the ground and that Washington is in discussions with 14 more on providing either combat or humanitarian troops.

Rumsfeld acknowledged, however, that the anti-American resistance in Iraq is learning to stay one step ahead of the technologically superior U.S. military.

"The remnants of the regime are going to school on us," he said. "They watch what takes place and then they make adjustments. The test is who's going to outlast the other, and the answer is we're going to outlast them."

Tokyo was the second stop on an Asia tour that is Rumsfeld's first since becoming secretary of defense nearly three years ago.

After two days in Japan, to include a visit Sunday with American troops stationed on the southern Japanese island of Okinawa, Rumsfeld was headed to Seoul, where the South Korean government also dealt the Pentagon a setback this week by pledging a smaller troop deployment to Iraq than Washington had hoped for. It also is unclear how soon the 3,000 South Korean troops will go.

Rumsfeld has said repeatedly that the Bush administration wants countries to contribute troops to Iraq only if they feel it is in their self-interest - and in numbers that suit them. But the timing of the announcements by Tokyo and Seoul - while Rumsfeld was still en route - gave weight to the perception that even the administration's best allies are doubtful of progress in Iraq.

And in recent days Rumsfeld has underscored how difficult these troop decisions have become.

"It's a dangerous country, it's a violent country," he said Thursday in Guam. "It's been a violent country for a long time and it very likely will be for a long time. Certainly people need to participate there with their eyes open."

Speaking to U.S. troops over lunch at Andersen Air Force Base on the north end of Guam, Rumsfeld said today that stabilizing Iraq is "a tough, dangerous business," and that while progress has been made in the six-plus months since major combat ended May 1, "we have a way to go" before the situation is stable enough to transfer control of the country back to the Iraqis.

Rumsfeld also said the Bush administration has abandoned its original plan to restore sovereignty to the Iraqis only after they have written and ratified a new constitution and held elections.

"The experts say to do that would take a very long period of time - a couple of years," he said.

The U.S.-appointed Iraqi Governing Council has "come up with ideas," presented to President Bush through L. Paul Bremer, the top American administrator in Iraq, on how to "find some transfer of responsibility at a pace that is earlier" than the projected two-year timetable, he said.