FILE This April 22, 2010, photo shows the international border in Nogales, Ariz. The first of 532 National Guard troops began their mission in the southern Arizona desert on Monday, Aug. 30, 2010 under President Barack Obama's plan to beef up U.S.-Mexico border security. AP photo/Matt York

PHOENIX - The chief of homeland security may be promising to keep the Guard on the border beyond June 30.

But officials from the National Guard said Wednesday they have no such notice. And unless they hear otherwise, they plan to start removing soldiers within days.

"We have not heard anything," said Capt. Valentine Castillo.

Castillo said the mission, approved last year, is slated to wrap up on June 30. which requires the "ramp-down" process to start by the end of the week.

That's also the assessment at the National Guard Bureau in Washington.

"We are on a glide path to end the mission," spokesman Jon Anderson said.

The moves come a week after the Department of Homeland Security publicly confirmed it wants to keep the soldiers there through the end of the federal fiscal year on Sept. 30.

But at this point, that remains little more than a proposal, as the agency has not yet received the necessary congressional approval to shift funds to pay the tab. Homeland security officials estimate it costs about $10 million a month to keep the 1,200 soldiers in place.

Janet Napolitano, the homeland security chief, has boasted of the success of the yearlong program. Her agency released statistics saying the soldiers have assisted Customs and Border Protection with seizing more than 14,000 pounds of drugs as well as providing information leading to the apprehension of more than 7,000 people trying to cross the border illegally.

But the pronouncement that the Obama administration wants the soldiers to stay, at least for three more months, also has political implications.

It comes as the president, in pronouncing the border more secure than ever, is pushing Congress to enact what he calls comprehensive immigration reform. That includes not only revamping how people can come to work legally in this country but also finding a way to legitimize the status of about 11 million illegal immigrants already in the country.

At the same time, the administration is facing calls by some, including Arizona's two Republican senators, to immediately put 3,000 Guard soldiers just along Arizona's international border. The current one-year deployment involves only 560 troops.

Castillo said absent specific orders from Washington, the Arizona National Guard cannot keep soldiers in place on the chance the mission will be extended. It is logistically impossible to keep all the troops deployed while awaiting word, and wrapping things up by June 30 takes time.

"It's a gradual process," he said.

"We have to turn in equipment," Castillo explained. He also said it takes time to ensure that when the soldiers "come off of orders" that all the administrative paperwork is in order.

"It's just like when they came on orders," he said, with several months necessary to get the units out into the field.