Pervez Musharraf, Pakistan’s president, on Tuesday swore in the country’s new prime minister – as two senior US officials arrived for discussions on Islamabad’s role in the Washington-led “war on terror”.

John Negroponte, the US deputy secretary of state, and Richard Boucher, the assistant secretary of state for south Asia, met Mr Musharraf and General Ashfaq Kiyani, the recently appointed army chief.

But their meetings with Asif Ali Zardari, co-chairman of the Pakistan People’s party, and Nawaz Sharif, leader of the Pakistan Muslim League-Nawaz Sharif, who together lead the new ruling coalition, attracted greater attention.

Senior figures from the two parties said the US officials appeared to have come in search of assurances about Pakistan’s continued support for anti-terrorism operations.

Comments by newly elected politicians have prompted speculation that the ruling coalition might go soft on radical militants and resist covert operations against them, such as the use of pilotless drones believed to be operated by the US Central Intelligence Agency along the Afghan border. Western diplomats say those border regions have become a haven for militants belonging to al-Qaeda and the Taliban who fled Afghanistan after the US-led invasion in 2002.

US officials said the visit was arranged well before Tuesday’s oath-taking by Yusuf Raza Gilani, the new PM, and was in no way timed to coincide with the latest political developments. After meeting the two US officials, Mr Sharif said that he had told them parliament would decide how Pakistan should best tackle Islamic extremism.