The U.S. Defense Department has neither sought nor received assurances that the Pakistani army will not stage a coup even though there is near-open conflict between the civilian and military leadership, a Pentagon spokesman said Wednesday.

Pakistan's president left the country Thursday for what was described as a one-day private visit to Dubai, amid a deepening crisis between the government and the powerful military, officials said.

Pakistan's Supreme Court on Tuesday warned it could disqualify both the president and prime minister from office for disobeying its orders to re-open high profile corruption cases.

Pakistan on Friday rejected a U.S. probe into the killing of 24 Pakistani soldiers, extending a crisis in its U.S. alliance now overshadowed by a showdown between the government and military in Islamabad.

Pakistan, enraged by a NATO cross-border attack that killed 24 soldiers, could end support for the U.S.-led war on militancy if its sovereignty is violated again, the foreign minister said, warning “enough is enough.”

A senior Pakistani army official has said a NATO cross-border air attack that killed 24 soldiers was a deliberate, blatant act of aggression, hardening Pakistan's stance on an incident that could hurt efforts to stabilize Afghanistan.

Thousands gathered outside the American consulate in the city of Karachi on Sunday to protest against a NATO cross-border air attack that killed 24 Pakistani troops and is threatening a strategic alliance between the countries.

Pakistan on Saturday accused NATO helicopters and fighter jets of firing on two army checkpoints in the country's northwest, killing 24 soldiers. Islamabad retaliated by closing the border crossings used by the international coalition to supply its troops in neighboring Afghanistan.

The Pakistani and Chinese attack choppers swoop low across the valley, strafing a mock terrorist hideout and a bomb-making factory. Then a joint commando team storms the camp -- to the gentle applause of top brass from both nations watching from the stands.

Pakistan's most troubled foreign relationships have improved in recent months, its top diplomat said on Saturday, pointing to upcoming trade talks with New Delhi and broad agreement on regional security goals with Washington as evidence.