The Philippines and the United States are examining other options in the fight against Abu Sayyaf Muslim extremists after failing to agree on a combat role for U.S. troops, Defense Secretary Angelo Reyes said Monday.

Returning from talks in Washington with Defense Secretary Donald Rumsfeld, Reyes did not say how long it would take to find an alternative strategy to a scotched U.S. plan to send more than 1,000 troops to the southern island of Jolo.

Pentagon officials had described the deployment as "joint operations" that would have drawn Americans into battle.

That wording caused an uproar in the Philippines. Newspapers, lawmakers and left-wing groups accused the government in Manila of violating the constitution that bars foreign troops from combat.

The government insisted that U.S. troops would only train and advise, as in joint exercises conducted last year that routed Abu Sayyaf guerrillas on neighboring Basilan island.

Philippine military officials recently said they had underestimated by nearly one half the number of the Abu Sayyaf's ranks, whose campaign of kidnappings and killings since 2000 has scared away foreign tourists and investment. The military estimates there are 380 guerrillas on Jolo and 80 on the neighboring island of Basilan.

Reyes said Monday that the two sides have agreed to "consider other options" and said Washington and Manila must still resolve legal and constitutional issues. He gave no time frame.

"We're not going to do anything that will violate our constitution and our laws," Reyes told reporters.

Both governments agreed that the operations should put more emphasis on building the Philippine military's abilities to deal with terrorism. That includes securing real-time intelligence information, tactical mobility and secure communications, Reyes said.

While the United States wants to call the activities combined operations, the Philippines would like to use the term training exercises, he said.

For the United States, "you can never have training, and it can never be an exercise if it is done in a hostile area, where the chances of being exposed to hostile enemy fire is high, or even probable, or even minuscule," Reyes said.

But for the Philippines, training involves a test mission in which students are sent to a hostile area and are involved in actual combat operations, he said.