The United States will keep F-16 fighter jets and Patriot anti-missile weapons in Jordan after a joint military exercise ends this month, a US defense official said Thursday.

The US administration, which is weighing a decision to arm rebels fighting in neighboring Syria's civil war, also planned to keep a unit of US Marines on amphibious ships off the coast after consultations with Jordanian leaders, the official told AFP on condition of anonymity.

The warplanes, anti-missile systems and warships had been sent to Jordan for a major exercise, dubbed Eager Lion, but officials decided to keep the troops and weapons in place on the request of Jordan, which is anxious about a spillover of violence and a growing influx of refugees from the conflict.

"It was decided the assets would remain in place," said the official.

The 26th Marine Expeditionary Unit taking part in the drill consists of about 2,400 troops, which arrived in a group of three amphibious ships, including the USS Kearsarge.

Officials declined to say how many F-16 jets had been deployed.

The move came as President Barack Obama's deputies reviewed possible options to supply weapons to Syria's rebel forces, with top officials attending a White House meeting on the issue Wednesday.

Secretary of State John Kerry called off plans for a trip to the Middle East to take part in the discussions.

The US official said one option under serious consideration would have the United States contribute funds that other governments -- including European allies -- could use to purchase weapons for the rebels, who have suffered serious setbacks in recent fighting.

"There would be pooled funds. That would enable other countries to draw from the pool to provide weapons," the official said, adding that no final decision had been made.

The option to provide funds was first reported by The Wall Street Journal, which cited a plea from a top rebel commander, General Salim Idris.

The general warned Aleppo could fall to Syrian regime troops without the delivery of arms and ammunition, including anti-tank and anti-aircraft weapons, the Journal said.