VIENNA, Austria (AP) - Washington's ragtag coalition in Iraq continues to crumble, diluting the U.S.-led effort to secure the country amid mounting pressure to start bringing American troops home next year.

Though many countries that sent small but mostly symbolic contingents insist they have no plans to pull out, Bulgaria and Ukraine will begin withdrawing their combined 1,250 troops this month.

Meanwhile, key allies including Australia, Britain, Italy, Japan, Poland and South Korea are mulling reductions or pullouts, some as early as spring. If they all follow through, the coalition would lose more than 15,000 troops _ a blow to the Pentagon as it trains Iraqis to take over the most dangerous peacekeeping tasks as part of an eventual exit strategy.

"The vibrations of unease from within the United States clearly have an impact on public opinion elsewhere," said Terence Taylor, who runs the Washington office of the International Institute for Strategic Studies. "Public opinion in many of these countries is heavily divided."

Although the nearly 160,000-member U.S. force in Iraq dwarfs the second-largest contingent _ Britain's 8,000 troops, backed up by 2,000 others in the Gulf region _ its support has shrunk to just under 24,000 mostly non-combat personnel provided by 27 countries.

At its height in the months after the March 2003 U.S.-led invasion, the multinational force numbered about 300,000 soldiers from 38 countries. But the coalition has steadily unraveled as the military death toll rises and angry publics clamor for their troops to come home.

This past spring, the Netherlands had 1,400 troops in Iraq. Today, there are just 19, including a lone Dutch soldier stationed in Baghdad.

Ukraine's remaining 876 troops in Iraq are due home by Dec. 31, fulfilling a campaign pledge by President Viktor Yushchenko, who came to power in January. Eighteen Ukrainian soldiers have died and 32 others have been wounded.

"The military mission is over," Defense Minister Anatoliy Grytsenko said after returning from a two-day trip to Iraq last month. "Now is the time for diplomats, industry workers and businessmen to have their word."

Bulgaria, too, is pulling out its 380 troops after Dec. 15 parliamentary elections, Defense Minister Veselin Bliznakov said.

Underscoring the mounting opposition in nearly all coalition countries, a poll published in Japan's Asahi newspaper this week showed 69 percent of respondents opposed extending the mission, up from 55 percent in a previous survey in January. No margin of error was given.

Japan's Kyodo News service reported Wednesday that Prime Minister Junichiro Koizumi's Cabinet would decide on Dec. 8 to allow its 600 troops to stay for an additional year, but that the government still could decide later to withdraw the troops around May.

A British drawdown would be the most dramatic.

Although Prime Minister Tony Blair's government insists there is no timetable for a withdrawal and British forces will leave only when Iraqi troops are capable of taking over, Defense Secretary John Reid suggested last month that a pullout could begin "in the course of the next year."

South Korea, the second-largest coalition partner after Britain, is expected to bring home about 1,000 of its 3,200 troops in the first half of 2006. The National Assembly is likely to vote on the government-proposed drawdown sometime this month.

Italy's military reportedly is preparing to give parliament within a few weeks a timetable for a proposed withdrawal of its 2,800 troops, most of whom are based in the southern city of Nasiriyah.

The center-right government of Premier Silvio Berlusconi has said it plans to withdraw the forces in groups of 300, but in accordance with the Iraqi government and coalition allies.

Poland, which has 1,400 troops providing security and training Iraqi soldiers and heads a multinational division in south-central Iraq, is expected to decide by mid-December whether to extend its mission beyond Dec. 31.

New Polish Defense Minister Radek Sikorski visits Washington this weekend for talks with U.S. officials on whether to maintain a presence in Iraq or withdraw as the former leftist Cabinet had planned to do in January.

"Some formula of advisory-stabilizing mission could remain on a smaller scale, of course, and our commanders are prepared for several variants," Col. Zdzislaw Gnatowski of the Polish army's general staff told The Associated Press.

Air Chief Marshal Angus Houston, the Australian Defense Force chief, has said about 450 troops in the southern province of Muthanna could be sent home by May. Australia has roughly 900 troops and support personnel scattered around Iraq.

U.S. President George W. Bush, struggling to shore up the crumbling coalition, made Mongolia a stop on his recent Asia trip and praised its force of about 120 soldiers in Iraq as "fearless warriors."

Many coalition members have pledged to keep troops in Iraq for all of 2006; at least one, Lithuania, has committed to the end of 2007. And the coalition is still drawing new members, most recently Bosnia, which sent 36 experts in June to help destroy unexploded ordnance.

"We are getting letters of gratitude from the U.S. commanders for our peacekeepers' excellent service," said Ilgar Verdiyev, a Defense Ministry spokesman in Azerbaijan, which has 150 troops and is one of the few mostly Muslim countries to contribute.