The U.S. military will have greater access to bases across the Philippines under a new 10-year agreement set to be signed Monday in conjunction with President Barack Obama's visit and seen as an effort by Washington to counter Chinese aggression in the region.

U.S. and Filipino officials confirmed the deal ahead of Obama's stop and portrayed it is as a central part of his weeklong Asia swing.

The Enhanced Defense Cooperation Agreement would give American forces temporary access to selected military camps and allow them to preposition fighter jets and ships.

It was to be signed Monday at the main military camp in the Philippine capital, Manila, before Obama arrived on the last leg of a four-country Asian tour, following stops in Japan, South Korea and Malaysia.

A Philippine government primer on the defense accord that was seen by The Associated Press did not indicate how many additional U.S. troops would be deployed "on temporary and rotational basis." It said that the number would depend on the scale of joint military activities to be held in the camps.

The size and duration of that presence has to be worked out with the Philippine government, said Evan Medeiros, senior director for Asian affairs at the White House's National Security Council.

Medeiros declined to say which specific areas in the Philippines are being considered under the agreement, but said the long-shuttered U.S. facility at Subic Bay could be one of the locations.

Two Philippine officials confirmed the agreement to the AP before the White House announcement. The officials spoke on condition of anonymity because they were not authorized to discuss details of the pact before it was signed.

The defense accord would help the allies achieve different goals.

With its anemic military, the Philippines has struggled to bolster its territorial defense amid China's increasingly assertive behavior in the disputed South China Sea.

Manila's effort has dovetailed with Washington's intention to pivot away from years of heavy military engagement in the Middle East to Asia, partly as a counterweight to China's rising clout.

"The Philippines' immediate and urgent motivation is to strengthen itself and look for a security shield with its pitiful military," Manila-based political analyst Ramon Casiple said. "The U.S. is looking for a re-entry to Asia, where its superpower status has been put in doubt."

The convergence would work to deter China's increasingly assertive stance in disputed territories, Casiple said. But it could further antagonize Beijing, which sees such tactical alliance as a U.S. strategy to contain its rise, and encourage China to intensify its massive military buildup, he said.

Hundreds of American military personnel have been deployed in the southern Philippines since 2002 to provide counterterrorism training and serve as advisers to Filipino soldiers, who have battled Muslim militants for decades.

The agreement states that the U.S. would "not establish a permanent military presence or base in the Philippines" in compliance with Manila's constitution. A Filipino base commander would have access to entire areas to be shared with American forces, according to the primer.

There will be "utmost respect for Philippine sovereignty," it said.

Disagreements over Philippine access to designated U.S. areas within local camps had hampered the negotiations for the agreement last year.

The agreement would promote better coordination between U.S. and Filipino forces, boost the 120,000-strong Philippine military's capability to monitor and secure the country's territory and respond more rapidly to natural disasters and other emergencies.

"Pre-positioned materiel will allow for timely responses in the event of disasters -- natural or otherwise," the primer said.

While the U.S. military would not be required to pay rent for local camp areas, the Philippines would own buildings and infrastructure to be built or improved by the Americans and reap economic gains from the U.S. presence, it said, adding the pact was an executive agreement that would not need to be ratified by the Philippine Senate.

The presence of foreign troops is a sensitive issue in the Philippines, a former American colony.

Left-wing activists have protested against Obama's visit and the new defense pact in small but lively demonstrations. They say the agreement reverses democratic gains achieved when huge U.S. military bases were shut down in the early 1990s, ending nearly a century of American military presence in the Philippines.

The Philippine Senate voted in 1991 to close down U.S. bases at Subic and Clark, northwest of Manila. However, it ratified a pact with the United States allowing temporary visits by American forces in 1999, four years after China seized a reef the Philippines contests.

Following the Sept. 11, 2001, attacks in the United States, hundreds of U.S. forces descended in the southern Philippines under that accord to hold counterterrorism exercises with Filipino troops fighting Muslim militants.

This time, the focus of the Philippines and its underfunded military has increasingly turned to external threats as territorial spats with China in the potentially oil- and gas-rich South China Sea heated up in recent years. The Philippines has turned to Washington, its longtime defense treaty ally, to help modernize its navy and air force, which are among Asia's weakest.

Chinese paramilitary ships took effective control of the disputed Scarborough Shoal, a rich fishing ground off the northwestern Philippines, in 2012. Last year, Chinese coast guard ships surrounded another contested offshore South China Sea territory, the Second Thomas Shoal, where they have been trying to block food supplies and rotation of Filipino marines aboard a grounded Philippine navy ship in the remote coral outcrops.

The dangerous standoff has alarmed Washington, which called China's actions provocative.

China has ignored Philippine diplomatic protests and Manila's move last year to challenge Beijing's expansive territorial claims in the South China Sea before an international arbitration tribunal. It has warned the U.S. to stay out of the Asian dispute.