TAIPEI, Taiwan (AP) — The United States has appointed a new representative to Taiwan, as China boosts its threats against the self-ruled island following the election of a new president who wants the territory to maintain its de-facto independence.

China claims Taiwan as its own territory and this week staged naval and air force drills that surrounded the island in a simulated blockade.

The American Institute in Taiwan that acts as the de-facto embassy in Taipei said Wednesday that veteran diplomat Raymond Greene would take over from Sandra Oudkirk beginning this summer.

The U.S. cut formal diplomatic ties with Taiwan in 1979 and established official relations with the People’s Republic of China, then a Cold War ally against the Soviet Union. Despite an absence of formal relations with Taiwan, the U.S. is the island’s strongest ally and is obligated under a 1979 law to help Taiwan protect itself from invasion.

Despite China’s intimidation, life carried on as usual in Taiwan, with politics dominated by arguments over legal changes that could make it easier for the minority Nationalist Party to cut deals with China’s ruling Communist Party, potentially undercutting Taiwan’s international competitiveness, financial advantages and high-tech economy based on its production of the most advanced computer chips.

Taiwan President Lai Ching-te took office May 20 and urged Beijing to stop its military intimidation and said Taiwan was “a sovereign independent nation in which sovereignty lies in the hands of the people.”

Greene has previously served as deputy head of AIT, as well as at the missions in Tokyo and held various roles in Washington, largely focused on economic relations. His appointment comes as Sen. Tammy Duckworth, D-Ill., and Sen. Dan Sullivan, R-Alaska, led a delegation to Taiwan emphasizing strong bipartisan support for the island.