In a sign of hardening US rhetoric against Iran and an effort to shift some blame for the turbulence in Iraq, President George W. Bush on Monday accused Tehran of supplying components for some of the most powerful improvised explosive devices used in Iraq.

“Coalition forces have seized IEDs and components that were clearly produced in Iran. Such actions, along with Iran’s support for terrorism and its pursuit of nuclear weapons, are increasingly isolating Iran,” Mr Bush said in a speech at George Washington University. He bluntly warned: “The situation in Iraq is still tense.”

The speech was the first in a series by Mr Bush ahead of the third anniversary of the start of the war. The speaking tour is designed to halt the slide in his domestic approval ratings and defend progress in Iraq. Last week Zalmay Khalilzad, the US ambassador to Baghdad, said the US had opened “Pandora’s box” in Iraq, an assessment reinforced by the State Department’s annual human rights report, which highlighted sectarian warfare between insurgents and interior ministry death squads.

Mr Bush was explicit about the challenges in Iraq, acknowledging that its police forces had lagged behind the Iraqi army and that there had been problems with infiltration by local militias. “We’re working with the Iraqi leaders to find and remove any leaders in the national police who show evidence of loyalties to militias.”

The US was now trying to make the police a “truly national institution” by addressing the fact that police recruits had been overwhelmingly drawn from the Shia majority, with less than 1 per cent Sunni enlistment.

In contrast to speeches early last year, which were infused with idealism over Iraq being a beacon of democracy in the Middle East, the speech concentrated on details of building up Iraq’s army. In the wake of the sectarian attacks following the bombing of the Golden Mosque of Samarra, Mr Bush said it was the “Iraqi security force, not coalition forces, that restored order”.

He offered two examples of incidents where the fact that Iraqi troops were in the lead had prevented violence, saying “because Iraqi troops spoke their language and understood their culture, they were able to convince the Iraqi militia to leave peacefully

Meanwhile, Scott McClellan, White House spokesman, on Monday hit back at a call from Russ Feingold, a senator from Wisconsin and potential 2008 presidential candidate, to censure Mr Bush for his decision to side-step congressional approval to eavesdrop on the international phone-calls of those suspected of ties to al-Qaeda. “It would be interesting to see how many Democrats actually agree with the view of Senator Feingold. Do Democrats support Senator Feingold’s view, or do they support this vital program? ”

Copyright The Financial Times Limited 2018. All rights reserved.

Comments have not been enabled for this article.