The United States will upgrade and build facilities on Philippine military bases this year, Manilas defense minister said on Thursday, bolstering an alliance strained by President Rodrigo Dutertes opposition to a U.S. troop presence.

The Pentagon gave the green light to start the work as part of an Enhanced Defence Cooperation Agreement (EDCA), a 2014 pact that Duterte has threatened to scrap during barrages of hostility towards the former colonial power.

"EDCA is still on," Defence Secretary Delfin Lorenzana told a news conference.

EDCA allows the expansion of rotational deployment of U.S. ships, aircraft and troops at five bases in the Philippines as well as the storage of equipment for humanitarian and maritime security operations.

Lorenzana said Washington had committed to build warehouses, barracks and runways in the five agreed locations and Duterte was aware of projects and had promised to honor all existing agreements with the United States.

This week, Republican U.S. Senator John McCain, who headed the U.S. Senates Armed Services Committee, proposed $7.5 billion of new military funding for U.S. forces and their allies in the Asia-Pacific.

The geopolitical landscape in Asia has been shaken up by Dutertes grudge against Washington, his overtures towards erstwhile adversary China, and the election of U.S. President Donald Trump, whose administration has indicated it may take a tough line on Chinas activities in the South China Sea.

The Philippines has said it wants no part in anything confrontational in the strategic waterway and will not jeopardize promises of extensive Chinese trade and investment, and offers of military hardware, that Duterte has got since he launched his surprise foreign policy shift.

Lorenzana said the Philippines had asked China for two to three fast boats, two drones, sniper rifles and a robot for bomb disposal, in a $14 million arms donation from China.

The arms package would be used to support operations against Islamist Abu Sayyaf militants in the southern Philippines, he said.

"If these are quality equipment, we will probably buy more," he said.

Lorenzana said Russia was offering hardware such as ships, submarines, planes and helicopters.

As with China, those offers have come as a result of a charm offensive by Duterte, who has praised Russia and its leadership. He last year said if Russia and China started a "new order" in the world, he would be the first to join.

Duterte was infuriated by U.S. expressions of concern about extra-judicial killings in a campaign against drugs he launched after he took office in June.