The United States has agreed to provide $15.5 million to help the Philippines guard its southern maritime borders against pirates, smugglers and militants, documents showed on Tuesday. According to a Philippine military report seen by Reuters, the US Department of Defense will fund a navy plan to acquire and install a network of high-frequency radio communications equipment for the southern region of the archipelago. The Sulu and the Celebes seas, which separate the Philippines from Malaysia and Indonesia, contain busy shipping lanes and fishing areas but are also infested by pirate gangs and rebels. Washington has also agreed to train, equip and help build up the Philippine military's naval defense capability under its 2007 National Defense Authorisation Act. About $4.4 million of the funds would be used to upgrade ageing UH-1H helicopters. Since 2002, the United States, Manila's closest security ally, has deployed hundreds of its troops to help train and advise Filipino soldiers to fight rebels. During the same period, the United States also provided about $500 million for military assistance and development projects to win over the Muslim minority in the mainly Catholic country. A senior official at the Philippines' Department of National Defence told Reuters the United States was also helping Malaysia and Indonesia, both Muslim-majority nations, set up similar maritime border security programmes to prevent militants from gaining access to these waters. Washington has allocated about $60 million under its section 1206 of the National Defence Authorisation Act in the fiscal year 2007 to help the three Southeast Asian states tighten their borders against movements of weapons, contraband and militants. The chairman of the US Joint Chiefs of Staff, Admiral Mike Mullen, did not refer to the maritime border project when he met senior Philippine armed forces officials this week although he was briefed on anti-militant operations in the south.