WASHINGTON – As Congress wrestles over the future of the Iraq war, Iraqi leaders have resigned themselves to the likely withdrawal of some U.S. troops, the country’s ambassador to the United States said Tuesday, because benchmark goals are unlikely to be met.

Ambassador Samir Sumaidaie also said there is insufficient time in the next two months for the U.S. military’s “surge” strategy to prove itself, an indication that he expects little progress on the U.S.-designated 18 measures of success by the time a pivotal American military assessment is compiled in September.

He said Iraqi leaders are engaged in a desperate balancing act. “They are juggling so many balls, and they know they have been handed even more balls,” he said. “And suddenly, one of the hands will have to go.”

Bush has sought to prevent Congress from judging his strategy before the mid-September assessment, but Sumaidaie expressed doubt that much will change, even with U.S. troop levels increased to about 158,000.

“I think September frankly is too soon to really show anything more than an inkling of its potential,” Sumaidaie said in a briefing at the Iraqi Embassy.

In Washington, Democrats steered the Senate into an all-night session Tuesday, but conceded they were unlikely to gain the votes needed to advance troop withdrawal legislation blocked by Republicans.

“We have no alternative except to keep them in session to explain their obstruction,” said Senate Majority Leader Harry Reid of Nevada.

Capping the overnight debate will be a test vote planned for today; Democratic officials conceded they were likely to get 52 or 53 votes at most, well short of the 60 needed to force a final vote on the measure.