The Philippine president said Wednesday she would weather growing criticism against a planned U.S. military presence in her country, aimed at helping deliver a fatal blow to the Muslim extremist group Abu Sayyaf.

The United States is sending troops to train Philippine soldiers against Abu Sayyaf, which has been linked to Usama bin Laden's Al Qaeda network, as an extension of the war against terrorism.

Defense Secretary Donald H. Rumsfeld said Wednesday at the Pentagon that so far up to 250 U.S. troops were in the country and "several hundred more" would follow. A "small number" of the Americans were on the southern island of Basilan, one of the areas where Philippine forces have been battling Abu Sayyaf.

Philippine officials say the American contingent would total about 660 troops, including 160 U.S. Army special forces, and some of them will be allowed to work on the front lines in the islands of the southern Philippines, where Abu Sayyaf is holding two Americans and a Filipino hostage.

President Gloria Macapagal Arroyo said the U.S. troops will only train Filipinos and will not violate a constitutional ban on foreign combat troops on Philippine soil, she said.

The new U.S. presence is sparking increasing protests from the Muslim minority, some of Arroyo's left-wing supporters and the mainstream political opposition. Along with concerns over foreign troops on the nation's soil, the possibility of an American firing at a Filipino — even a violent radical — has sparked criticism.

"I will weather the criticisms because in the end, if we get the Abu Sayyaf, we would have been victorious," Arroyo said.

The six-month exercise could see U.S. troops advising Filipinos in training camps — and combat zones — as early as next month.

Terrorism "is a global problem that we are addressing globally, not just in Afghanistan," Rumsfeld told reporters Wednesday. The United States "does have military people ... working with the Philippine government from a training and exercise standpoint to help them deal with this problem."

He would not say how the United States would respond if the Philippines asked U.S. troops to get involved in fighting more directly. "We would address [the request] ... as a nation whose president has announced that we are determined to find terrorist networks and do what we can to help root them out," he said.

Philippine National Security Adviser Roilo Golez said the government will allow the U.S. soldiers to carry weapons into combat zones, though they would only fire in self-defense. Golez said fewer than 200 U.S. soldiers will be allowed into combat zones, split into groups of 12 for every 400 or so Filipinos.

The U.S. troops are to train Filipinos in night helicopter flying, psychological operations and intelligence work.

Besides the training, the two countries are discussing a proposal to allow the military of one country to rapidly acquire supplies and spare parts from the other, Defense Secretary Angelo Reyes said Wednesday.

One potentially controversial provision would allow Washington to store spare parts and supplies that are not readily available in the Philippines.

The violence of the Abu Sayyaf has scared off foreign investment and destabilized parts of the southern region of Mindanao, home to the Muslim minority in the predominantly Roman Catholic nation.

The Abu Sayyaf, with about 800 fighters, continued a tradition of kidnappings last May 27 when it abducted 20 tourists and workers from a beach resort.

They beheaded some, including Corona, Calif. resident Guillermo Sobero. They released others, some reportedly for ransom, and still hold Kansas missionaries Martin and Gracia Burnham and Filipino nurse Deborah Yap.

While eradicating the Abu Sayyaf would benefit the economy and political stability, opposition to U.S. help is growing.

"My worry is this: what if a Filipino farmer or even an Abu Sayyaf is killed by an American bullet fired by an American trooper?" said opposition Sen. Rodolfo Biazon, a former general. "What would be the reaction of nationalists?"