The number of US troops in Iraq could be cut to around 100,000 by the time the next president takes over at White House in 2009, US Defence Secretary Robert Gates said today.

President Bush has already endorsed plans for a gradual reduction of the current strength of 168,000 to around 135,000 by next summer, but has also signalled he believes the US must accept an “enduring” military operation in Iraq beyond his term in office.

Democrats, such as presidential frontrunner Hillary Clinton have dismissed that promise as “too little, too late,” but know there is little they can do to stop the war before the November, 2008 elections.

Mr Gates’s comments today may have been designed to shore up the fragile prospect of a political compromise on Iraq. “My hope is that the pace of the drawdown can continue at the same rate in the second half of the year as the first half of the year,” said the Defence Secretary.

Asked at a press conference if that meant a reduction to ten combat brigades, or about 100,000 troops, by January 2009, Mr Gates replied: “That would be the math.”

Mr Bush’s difficulty in persuading a sceptical Congress to back an “enduring” military presence in Iraq was underlined today by a White House admission that the Baghdad government was meeting just half of its objectives.

The report card sent to Congress yesterday marked Nouri al-Maliki’s government as “satisfactory” on nine of the 18 benchmarks for political progress set for it earlier this year. Among the targets missed were sharing oil revenues between regions and getting Iraqi security forces to operate independently.

A Government Accountability Office report last week was even more damning, suggesting that just three of these goals had been achieved.

In his televised address last night, Mr Bush insisted that “Iraq’s national leaders are getting some things done” but added that he had made clear “they must” do more to meet the benchmarks.

Democrats, who control both Houses of Congress, have been frustrated in legislative efforts to set a timetable for ending the war because so far they have lacked the majorities needed to overcome a presidential veto - or even the more limited number to stop Republican blocking tactics.

They plan fresh attempts this autumn with a Bill designed to attract support from moderate Republicans for narrowing the mission of a smaller military force to training Iraq’s military and police, protecting US assets and fighting terrorists. They also hope to ensure that troops spend equal periods of time at home and in the war zone, thereby limiting the numbers available for deployment.

Mr Bush, who today continued his political “surge” on Iraq with a visit to the Marine base of Quantico, Virginia, is seeking a compromise with Congress: cutting troop numbers while asking it to fund a long term military presence in Iraq that will “require US political, economic, and security engagement that extends beyond my presidency”.

Over an unspecified period of time the mission in Iraq “will evolve”, promised the president on Thursday, with troops switching “to a more limited set of tasks, including counter-terrorism operations and training, equipping, and supporting Iraqi forces”.

In his comments this week, Mr Bush has even replaced his many promises of “victory” - something most voters now regard as highly improbable in this war - with the more ambiguous term of “success”.

Democrats, however, remain distinctly unimpressed. Nancy Pelosi, the House of Representatives Speaker, said Mr Bush was “insulting the intelligence of the American people”. The most likely prospect now is of a stalemate with Congress struggling to pass binding legislation to end the war and Mr Bush unable to secure a lasting legacy in Iraq.

Times Recommends

• 'Great Schlep' may seal deal for Obama
• Hindu 'storm troopers' flex their muscles
• Ahtisaari: deserved reward for (failed) plan