WASHINGTON, (Reuters) – U.S. President George W. Bush will issue a report as early as Thursday likely to show only limited progress by Iraq’s government even as he scrambles to halt erosion of Republican support for an unpopular war.

The interim assessment demanded by the U.S. Congress could accelerate Democratic-led efforts to force Bush to start scaling back troop levels in Iraq more than four years after a U.S.-led invasion that toppled Saddam Hussein.

With Iraq still plagued by violence, the administration will have little choice but to concede that Iraqi leaders have not met some key security and political goals set for them by Bush and U.S. lawmakers to promote national reconciliation. But the administration is expected to take a glass-half-full approach, emphasizing hopeful signs since Bush ordered a U.S. troop buildup six months ago, including a drop in sectarian killings in Baghdad and increased arms seizures.

The New York Times and The Washington Post, quoting administration officials, reported the assessment would state that progress in the Iraq security plan was satisfactory on almost half the 18 benchmarks set by Congress, mostly related to military issues. The Post added the report found insufficient improvement in eight other benchmarks and mixed results in two others.

Facing a growing revolt by fellow Republicans skeptical of his Iraq policy, Bush is trying to buy time, urging lawmakers to hold fire until U.S. commanders and top diplomats deliver their full progress report in September. The White House has tried to keep expectations low. “It’s a snapshot,” said Bush’s press secretary, Tony Snow. He insisted this week’s midterm report could not yet gauge the success or failure of the troop increase because the last of the 28,000 additional forces arrived only two weeks ago. But the early assessment prepared by Gen. David Petraeus and U.S. Ambassador Ryan Crocker is seen as pivotal amid mounting pressure for Bush to change course. His public approval ratings have fallen to the lows of his presidency. With Republicans increasingly worried the Iraq war could cost them the White House in 2008, several prominent Bush allies like Indiana Sen. Richard Lugar have broken ranks.

Trying to calm dissent, Bush met Republican leaders at the White House and apparently gave some an overview of the interim report. “There is some good news in there, but there is some not-so-good news in there too,” a Republican aide said.

A U.S. official said that in rating progress on a series of “benchmarks” set for the Iraqi government of Prime Minister Nuri al-Maliki, “some are satisfactory and some are not.” The report is likely to acknowledge the Iraqis’ failure so far to meet objectives crucial to sectarian reconciliation, such as agreement on sharing oil revenues, scheduling of provincial elections and passage of de-Baathification laws.

Doubts also linger about the readiness of Iraqi security forces to assume a greater role from U.S. forces, crucial to any future drawdown of American troops.

In May, Congress agreed to continue funding the war for now but demanded Bush certify on July 15 and again on Sept. 15 that the Iraqis were living up to their political promises.

State Department spokesman Sean McCormack let slip that the assessment was expected on Thursday. The White House would only say it would be issued either on Thursday or Friday.