The Obama administration has delayed the shipment of four F-16 fighter jets to Egypt because of ongoing concerns about the political instability there. The Pentagon had said two weeks ago that it would continue with the delivery of the aircraft.

Pentagon press secretary George Little told reporters today, "Given the current situation in Egypt, we don't believe it is appropriate at this time to proceed with the delivery of F-16s to Egypt."

The United States will continue its broad military relationship with Egypt, so the upcoming joint exercise known as "Bright Star" will continue as scheduled later this year, Little said.

There's no time frame on the delay in delivery of the jets, Little said, adding that it is unrelated to the ongoing determination of whether a coup had taken place in Egypt, which would lead to a cut off of U.S. military aid. "The decision to delay doesn't necessarily reflect the outcome of that process," he said.

He described the situation in Egypt as "fluid," so "we think it's prudent at this stage to delay the F-16 delivery."

The four jets are among 20 F-16s that Egypt arranged to purchase from Lockheed Martin, along with parts, for about $3 billion and are being delivered in stages this year. The planned final shipment of eight F-16s scheduled for the December-January time frame is not affected by this decision, yet.

Little said Defense Secretary Chuck Hagel called Egyptian military leader Gen. Abdel-Fattah el-Sissi this morning to inform him of the delay in the delivery of the F-16s.

It was their 12th conversation since July 2, shortly before the military deposed President Mohammed Morsi. Little confirmed that Hagel also talked to el-Sissi about the military's call for mass protests Friday to give the army a mandate to fight "violence and terrorism."

A U.S. defense official said later that President Obama made the decision to delay the shipment of the aircraft Tuesday night.