US Senator John Kerry warned on Sunday that relations with key ally Pakistan were at a "critical moment". Kerry, speaking in the Afghan capital Kabul, said he was ready to listen to Pakistan's leaders but the discovery of the al Qaeda chief living close to Islamabad meant talks had to "resolve some very serious issues."
Pakistan's government, intelligence services and military have been widely accused of incompetence or complicity over the presence of bin Laden, who was killed by US commandos in a covert raid on May 2.
"We need to find a way to march forward if it is possible. If it is not possible, there are a set of downside consequences that can be profound," said Kerry, whose trip to the region has been endorsed by President Barack Obama.
Kerry, chairman of the influential Senate Foreign Relations committee, also repeated Washington's belief that Pakistani authorities know where Taliban safe havens harbouring the leaders of Afghanistan's insurgency are located.
"There is some evidence of Pakistan government knowledge of some of these activities in ways that is very disturbing," he told reporters, adding that he would raise the long-standing issue in Islamabad.
But Kerry also sought to dampen the diplomatic fallout from the bin Laden raid, which severely strained ties with the US and stirred renewed anti-American sentiment in Pakistan.
"It's important to try also to not allow the passions of a moment to cloud over the larger goal that is in both of our interests," he said in reference to efforts to combat Islamist militancy.
Kerry arrived on Saturday in Afghanistan, where 130,000 foreign troops are fighting against the worsening insurgency, holding talks with President Hamid Karzai and meeting US soldiers.