Vienna, Austria ? The Ukrainians are long gone. So are the Norwegians. The Italians and South Koreans are getting ready to leave, and the Britons and Japanese could begin packing their bags later this year.

Slowly but steadily, America’s allies in Iraq are drawing down or pulling out as Iraqi forces take more responsibility for securing the country. By year’s end, officials say, the coalition – now 25 nations supporting a dwindling U.S. contingent of 138,000 – may shrink noticeably.

The withdrawals and reductions will test the Iraqis’ ability to tamp down attacks and rebuild, said Anthony Cordesman of the Washington-based Center for Strategic and International Studies, warning in a new report: “It is too soon to predict the extent to which Iraqi forces can eventually replace coalition forces.”

Britain, with about 8,000 troops in Iraq, is the United States’ most important coalition ally. Officials repeatedly have said they hope to begin bringing home some of their troops this year, though Defense Secretary John Reid has played down recent reports that Britain has settled on a timetable for withdrawal.

“We are going to hand over to the Iraqi security forces … whenever they are ready to defend their own democracy. We are there as long as we are needed and no longer,” Reid told The Associated Press in a recent interview in London.

Poland’s new president, Lech Kaczynski, told the AP his country might keep its scaled-down contingent of 900 troops in Iraq into 2007.

But other countries have abandoned the coalition, shrinking the overall size of the force to 157,500, including the 138,000 U.S. troops.

In the months after the March 2003 invasion, the multinational force peaked at about 300,000 soldiers from 38 nations – 250,000 from the United States, about 40,000 from Britain, and the rest ranging from 2,000 Australians to 70 Albanians.

Among the larger contributors to pull out of Iraq was Ukraine, which withdrew its last contingent of 876 troops in December.

Many of the non-U.S. forces are in heavily Kurdish and Shiite regions that are relatively peaceful, unlike Sunni Arab flashpoints where American troops are concentrated.

Key coalition members such as South Korea and Italy – the United States’ No. 2 and 3 partners in Iraq after Britain – will begin drawing down this spring.

South Korean officials say they plan to bring home about 1,000 of their 3,270 troops in phases this year.

Italy, which has about 2,600 troops based in the southern city of Nasiriyah, announced last month it would withdraw all its forces by the end of 2006.

Japan, which has 600 non-combat troops in Samawah to purify water and carry out other humanitarian tasks, has officially denied media reports that it plans to begin bringing its forces home as early as March, with the withdrawal completed by May.

However, Japan’s Kyodo news agency quoted a senior government official last weekend as saying the country was planning an “exit from Iraq.”