MANILA - The Senate sent a nonbinding resolution to the government Tuesday calling for the re-negotiation of a security agreement with the United States because it violated the constitution.

The move came on a day two US Navy servicemen were killed when a convoy of military vehicles struck a crude land mine on the southern Jolo island in the Philippines.

Senators led by Miriam Defensor-Santiago, a political ally of President Gloria Macapagal Arroyo, argued the Visiting Forces Agreement (VFA) was a one-sided deal in favor of Washington.

"It's a simple resolution which does not have the effect of the law," said Sen. Miguel Zubiri, another Arroyo ally and majority floor leader at the Senate, adding the lawmakers were merely expressing a collective sentiment toward an issue.

But the government has responded positively, creating an inter-agency panel to review the agreement signed in 1998 and recommend whether Manila should keep or abrogate the treaty for a much better deal from the United States.

The senators said the VFA had not been beneficial to the Philippines because the United States failed to provided enough aid to modernize the country's military capabilities as well as guarantee the rights of Filipinos in criminal cases.

They also cited media reports which claimed US troops deployed in the southern Philippines had engaged in combat with Muslim rebels from the Abu Sayyaf. The agreement prohibits US troops from combat in the Philippines, allowing them to only train and advise Filipino troops.