Pakistan says it is doing all it can to stop militants infiltrating Afghanistan, but the US military says cross-border attacks in Afghan border areas increased sharply last year. The US bill, known as H.R. 1, calls for an end to US military assistance to Pakistan if it fails to stop the Taliban operating from its territory.
The bill has already been endorsed by the House of Representatives and will be sent to the Senate for consideration. The US embassy in Islamabad said linking aid to tackling the Taliban would be counter-productive to fostering a closer relationship with Pakistan, which was one of the bill's goals.
"While the US administration supports the underlying intent of H.R. 1, the US administration has serious concerns with several of the bill's provisions and does not support it in its current form," the embassy said in a statement late on Wednesday.
The United States and Pakistan were not only allies in the war on terrorism but also partners engaged in building a broad, long-term strategic relationship, it said. Pakistan had continued to demonstrate its commitment to co-operation with US counter-terrorism efforts, it said.
Pakistan, which has been battling militants on its side of the border, acknowledges that some insurgents are crossing into Afghanistan but says the insurgency there is essentially an Afghan problem. New US House of Representatives speaker Nancy Pelosi, under whom the bill was introduced, visited Pakistan last week and met President Pervez Musharraf.
The government did not say whether the bill was discussed but Musharraf said Pakistan's resolve to fight extremism and terrorism was unshakeable.