Manila  - The United States is ready to provide assistance to the Philippines in its efforts to free Italian and Swiss Red Cross personnel seized by Muslim militants on a southern island, a US embassy diplomat said Thursday.

"We stand ready to help our Philippine counterparts with whatever they might request, of course," Thomas Gibbons, US deputy ambassador and political affairs counsellor, told reporters at the opening ceremony for annual US-Philippine military training exercises.

Gibbons, however, stressed that US troops would not get involved in any direct operations to rescue the International Committee of the Red Cross workers, Swiss Andreas Notter and Italian Eugenio Vagni.

The Philippine constitution prohibits foreign troops from engaging in combat operations in the country.

Armed forces chief Alexander Yano said the Philippines would rely on its own troops to solve the hostage crisis but might seek "technical assistance" from the United States.

"Maybe medical air evacuation and maybe in transport of some equipment but other than that, as in the past, we have not utilized them [US troops] for any direct combat action," he said.

Government troops have set up a cordon around the lair of Muslim Abu Sayyaf rebels on Jolo island, 1,000 kilometres south of Manila, in a bid to secure the safe release of Notter and Vagni, who were seized on January 15 along with their Filipino colleague Mary Jean Lacaba.

Lacaba was freed April 2.

The government has sought the help of top Muslim clerics in the country in securing the release of the two remaining hostages.

The Abu Sayyaf has been threatening to kill the hostages if government forces do not pull out from a wide area of Jolo. Authorities have rejected the demand but vowed to ensure that none of the hostages were harmed.

The al-Qaeda-linked guerrillas have been blamed for some of the worst terrorist attacks and high-profile kidnappings in the Philippines. They have beheaded hostages, including an American tourist abducted in 2001, when authorities failed to meet their demands.(dpa)