By David Brunnstrom and Michael Martina

WASHINGTON, April 10 (Reuters) - Imposing tariffs on U.S. imports from the Philippines could affect the U.S. ally's ability to afford U.S. weapons systems and a long-discussed $5.58 billion plan to acquire F-16 fighter jets, Manila's ambassador to Washington told Reuters.

The Philippines faced levies of 17% on its exports to America after President Donald Trump announced global tariffs last week. On Thursday, Trump announced a 90-day pause on the "reciprocal tariffs" except those on goods from China, but the Philippines and other Southeast Asian countries still face a 10% levy for the next three months.

Philippine ambassador Jose Manuel Romualdez said Manila was keen to negotiate.

"Like most countries … we're trying to arrange for our minister of trade, for our presidential assistant on international investments and trade, to be able to come here to Washington and have a serious discussion on how we can go through this whole process … on the basis of what is mutually beneficial for both our countries," he said in an interview.

He referred to Washington's approval this month of the potential sale of F-16 aircraft made by Lockheed Martin LMT.N for an estimated cost of $5.58 billion and said tariffs could affect the Philippines economy and its ability to afford them.

"These F-16s ... are very expensive for us ... and we won't be able to afford it if, obviously, we won't have the resources to be able to buy them," he said.

Romuladez noted that the Philippines trade surplus with the U.S. was about $4.8 billion.

"The F-16 (deal) is $5.8 billion," he said. "So that's a $1 billion surplus in favor of the United States, if we do get to that point that we'll be able to buy that.

"It's a quid pro quo. And I think that President Trump has made it clear that tariffs are to balance it off … So if that's the policy, then we will do it."

Philippine officials say Manila is also interested in purchasing the Typhon missile system , which the U.S. has deployed in the Philippines for exercises and which experts say could have an important role in the event of a Chinese attack on the self-governed but Chinese-claimed island of Taiwan.

Romualdez, ambassador in Washington since 2017 during Trump's first term and a cousin of Philippines President Ferdinand Marcos Jr, said Manila's U.S. relationship was different to those of other countries given shared losses in World War Two.

He said a U.S. visit by Marcos to meet Trump that had been envisaged for the spring depended on their respective schedules, but could take place "any time between … April, May, June."

(Reporting by David Brunnstrom and Michael MartinaEditing by Don Durfee and Chizu Nomiyama)

((david.brunnstrom@thomsonreuters.com; +1 202-843-6366; @davidbrunnstrom;))