The United States, in perhaps its strongest language since the war on terrorism started 10 years ago, warned Pakistan that it would face serious consequences if it continued to tolerate safe havens for extremist organizations that kill Americans.

A top-power delegation of U.S. Secretary of State Hillary Clinton, Director of Central Intelligence David Petraeus and Chairman of the Joint Chiefs of Staff Gen. Martin E. Dempsey traveled to Islamabad to press their counterparts on a definitive choice: fighting terrorism or supporting them, The New York Times reported Thursday.

We're looking to the Pakistanis to lead on this because there's no place to go any longer. The terrorists are on both sides of the Afghan-Pakistani border, Clinton said, The Associated Press reported Thursday.  No one should be in any way mistaken about allowing this to continue without paying a very big price,

Clinton used a Thursday news conference to send a clear, unequivocal message to Pakistan saying it should help efforts to broker an end to the decade-long war in Afghanistan and crackdown on safe havens used by militants, reported Thursday.

Clinton: Pakistan Must Be Part of the Solution

They must be part of the solution and that means ridding their own country of terrorists who kill their own people and cross the border to kill in Afghanistan, Clinton said, reported. We're going to be fighting, we're going to be talking and we're going to be building. And they can either be helping or hindering, but we are not going to stop our efforts.

The United States' complex relationship with Pakistan has sunk to a new low in 2011 amid rising tensions and a series of point-to-point rows, including the arrest of a Central Intelligence Agency officer, the secret raid that killed Al Quaida Leader Osama bin Laden, and an attack on the U.S. Embassy in Islamabad, which U.S. officials blamed on elements within Pakistan's spy agency, the Inter-Services Intelligence.

Clinton reiterated calls for greater unity among the United States, Afghanistan and Pakistan. She categorized the Obama administration's strategy as fight, talk, build -- fighting the militants who reject peace negotiations, engaging in talks with those willing to put down their weapons, and continuing to build an Afghan government still plagued by dysfunction and rampant corruption, The Associate Press reported.