The U.S. is delaying delivery of four F-16 fighter jets to Egypt amid unrest following the military's overthrow of Mohammed Morsi as president.

"President Barack Obama made the decision to hold up the F-16 delivery while the administration continues to review options and consult with Congress on military assistance generally," Pentagon press secretary George Little on Wednesday. He said the decision was made given the overall situation in Egypt.

"We remain committed to the US-Egypt defense relationship... Moving forward, everything that we do and say will continue to be focused on hastening Egypt's return to a democratically elected government as soon as possible," he added.

As there is no timetable for proceeding with the delivery, Pentagon was not specific about the reasons for delaying it.

US Defense Secretary Chuck Hagel also called Egypt's military chief, General Sisi, on Wednesday to discuss the administration's decision.

The four F-16s are part of a previously arranged sale of 20 jets. Eight of the F-16s were delivered earlier this year; after the four originally set for delivery this week the final eight were to be sent later this year. Also on order by the Egyptian military are US-made M1A1 Abrams tanks; the administration has not yet decided whether to go ahead with those.

The delay is the first direct action the US has taken since the Egyptian military ousted Morsi and installed a new civilian government. Under US law, military aid to a country that underwent a coup d'etat must be suspended.

The Obama administration still has not decided whether to call Mursi's overthrow a coup. Egypt is a key ally in the Middle East and the Obama administration is reluctant to cut off the $1.3bn aid package it sends to Cairo every year.

This year's military exercise called Bright Star with Egypt is still scheduled to go ahead as planned. Bright Star has been a centerpiece of the two countries' military relations for decades.

It usually is held every other year, but the 2011 maneuvers were canceled following the revolution that ousted President Hosni Mubarak. This year's exercise is tentatively planned to begin in mid-September.

Source: Agencies