Ebrahim Noroozi, Associated Press
A Syrian woman who lives in Iran casts her ballot for her country's presidential election at the Syrian Embassy in Tehran, Iran, Wednesday, May 28, 2014, as expat voting started ahead of Syria's June 3 presidential election - a vote highly contentious amid the civil war but one that is widely expected to give the Syrian president a third seven-year term in office.

WASHINGTON — The White House soon may sign off on a project to train and equip moderate Syrian rebel forces, according to Obama administration officials. The move would significantly boost U.S. support for rebels seeking military help to oust Syrian President Bashar Assad.

President Barack Obama is considering sending a limited number of American troops to Jordan to be part of a regional training mission that would instruct carefully screened members of the Free Syrian Army on tactics, including counterterrorism operations, the officials said.

They said Obama has not given final approval and there still were internal discussion about the merits and potential risks.

The officials spoke on condition of anonymity because they were not authorized to discuss administration deliberations by name.

In a speech at the U.S. Military Academy on Wednesday, Obama was expected to frame the situation in Syria as a counterterrorism challenge and indicate he will expand assistance to the opposition, although he was not expected to announce the new program, the officials said.

"We look at the Syrian conflict as part of a broader counterterrorism challenge," White House press secretary Jay Carney told reporters traveling aboard Air Force One to the speech. "And that is why we're going to continue increasing our support to the moderate opposition to offer the best alternative to both the murderous Assad dictatorship and the extremists who have exploited the crisis in Syria for their own malign purposes."

He declined to offer further details ahead of Obama's remarks. "We have a range of options that we will continue discussing within the administration and with Congress," Carney said.

The State Department, Pentagon and U.S. intelligence agencies, along with many in Congress who back the move, have concluded Assad will not budge without a change in the military situation on the ground, according to the officials.

At the same time, there are growing fears about the threat from al-Qaida-linked and -inspired extremists fighting in Syria, the officials said.

The Senate Armed Services Committee last week passed a defense bill that authorizes the Defense Department to provide training and equipment elements of the Syrian opposition that have been screened.

The U.S. has covert support operations in place for the Syrian opposition, and it is not yet clear how the new program would work. The United States has spent $287 million so far in nonlethal aid on the civil war, now in its fourth year.

Rebel commanders for three years have asked the U.S. for lethal assistance as they've seen gains wiped out one after another. The U.S. has been reluctant to move to that kind of aid for fear weapons could end up in the hands of extremist rebels who might then turn on neighboring Israel or against U.S. interests.

The proposed mission would be coordinated by the U.S. but involve many of the regional players active in assisting the rebels, including Turkey, Jordan, Saudi Arabia, Kuwait and the United Arab Emirates, the officials said.

Saudi cooperation is critical and has been a main topic of conversation between Washington and Riyadh, including Obama and Saudi King Abdullah, in recent weeks, the officials said.

"We will also continue to increase our support for Syria's neighbors as they continue to host refugees and confront the terrorist threat emanating from Syria," Carney said.

The expected announcement also follows intense, high-level discussions between the United States and Jordan, which over the weekend expelled the Syrian ambassador as part of what is planned to be an escalation in the effort to isolate Assad.

Assad is running for re-election in a June vote that the U.S. and its allies have condemned as a farce.

Jordan's King Abdullah II was in Washington last week and met with Secretary of State John Kerry. Defense Secretary Chuck Hagel made a stop in Jordan this month during a Middle East trip.

The U.S. has roughly 1,500 military troops in Jordan, in addition to the approximately 6,000 that recently arrived there for a limited time to participate in the annual Eager Lion military exercise.

Eager Lion 2014 includes members of the Army, Navy, Air Force and Marines, as well as U.S. ships and aircraft. The exercise started this past weekend.

Last year, after Eager Lion 2013 finished, the U.S. left a detachment of F-16 fighter jets and a Patriot missile battery there and about 1,000 personnel associated with the aircraft and the missile system. There also is a staff of about 400 U.S. military in Jordan and there were troops there to assist the Jordanians with chemical weapons training.

Small teams of U.S. special operations forces also have rotated in and out of the country conducting exercises with Jordanian and Iraqi commandos. The last session was in April and another is scheduled for June.

AP White House Correspondent Julie Pace contributed to this report.