The United States' embassy in Islamabad suspended visa and routine consular services on Friday due to "heightened security", a spokesman said.
The embassy will provide emergency consular services for Americans and the routine operations will resume on Monday. The US consulates in Lahore, Karachi and Peshawar would be open today, the spokesman said.
The spokesman did not give details about the security concerns but the move appeared to be linked to heightened security across Pakistan on the occasion of Good Friday.
The Pakistani capital has also been targeted in a recent series of terrorist attacks, with a suicide bomber killing eight security personnel at a paramilitary camp in the heart of the city on April 4.
A statement issued by the US embassy said staff should be careful while travelling to public places, restaurants and hotels due to "serious security threats" to American citizens.
Offices of several international donor organisations in Islamabad would also remain closed today due to security threats, reports said.