George W. Bush will next week decide whether to maintain the current troop level of US troops in Iraq for the rest of his presidency, potentially leaving the next big decision on Iraq policy to his successor.

Mr Bush is considering recommendations made this week by his military advisers. Robert Gates, US defence secretary, and Admiral Mike Mullen, the chairman of the joint chiefs, recommended that the US withdraw only a small number of troops this year to preserve recent progress.

Mr Gates and Adm Mullen recommended that the Pentagon resume a drawdown early next year by not replacing an army brigade – roughly 3,500 troops – slated to return to the US. If Mr Bush accepts the recommendations, the next president will assume office with more than 140,000 troops in Iraq.

Violence across Iraq has dropped dramatically over the past year, partly because of the influx of the US “surge” forces, which left this summer. General David Petraeus, the top US commander in Iraq, originally wanted to maintain close to the current 15 combat brigades until next summer. In the end, however, he agreed to compromise with other senior brass in the Pentagon, who want to quickly free up troops for Afghanistan.

In a recent interview with the Financial Times, Gen Petraeus, who leaves Iraq later this month, said the coalition had to deal with some “wrinkles” after Georgia unexpectedly recalled 2,000 of its troops to fight in the conflict with Russia. Poland is soon expected to recall about 800 soldiers.

While the US wants to move forces into Afghanistan, officers also recognise that security gains in Iraq could be jeopardised by a hasty withdrawal. The military has expressed concern that the “Sons of Iraq” – groups of mostly Sunni former insurgents who changed sides to work with the Americans against al-Qaeda – could become disillusioned because of a clampdown by Nouri al-Maliki, the Iraqi prime minister. The move by Mr Maliki to arrest senior leaders has raised concerns about re-igniting sectarian tensions.

Mr Bush is due to speak at the National Defence University on Tuesday, and Mr Gates and Adm Mullen will appear on Capitol Hill to discuss Iraq the following day.

Separately, Iraq on Friday reacted angrily to claims in a new book that the US government had spied on the Iraqi government. In a book released on Monday, Bob Woodward, the veteran Washington Post reporter, says the US eavesdropped on Mr Maliki and other leaders.

Iraq said it would seek an explanation from the US. The disclosure comes at a sensitive time as both countries negotiated a complicated long-term security agreement.