WASHINGTON (AP) — United States (US) President Joe Biden is set to host President Ferdinand Marcos Jr of the Philippines for White House talks Monday as concerns grow about the Chinese navy’s harassment of Philippine vessels in the South China Sea.

Marcos’ visit to Washington comes after the US and the Philippines last week completed their largest war drills ever and as the two countries’ air forces on Monday will hold their first joint fighter jet training in the Philippines since 1990. The Philippines this year agreed to give the US access to four more bases on the islands as the US looks to deter China’s increasingly aggressive actions toward Taiwan and in the disputed South China Sea.

Meanwhile, China has angered the Philippines by repeatedly harassing its navy and coast guard patrols and chasing away fishermen in waters that are close to Philippine shores but that Beijing claims as its own.

Before departing for Washington on Sunday, Marcos said he was “determined to forge an ever stronger relationship with the United States in a wide range of areas that not only address the concerns of our times but also those that are critical to advancing our core interests.”

Monday’s Oval Office meeting is the latest high-level diplomacy with Pacific leaders by Biden as his administration contends with increased military and economic assertiveness by China and worries about North Korea’s nuclear program. Marcos’ official visit to Washington is the first by a Philippine president in more than 10 years.

The US president last week hosted South Korean President Yoon Suk Yeol for a state visit during which the two leaders introduced new steps aimed at deterring North Korea from launching an attack on its neighbours. Biden is scheduled to travel to Japan and Australia in May.

The two sides are expected to discuss the security situation and come out with new economic, education, climate and other initiatives as part of Marcos’ four-day visit to Washington, according to two senior Biden administration officials.

The officials, who briefed reporters on the condition of anonymity to preview the leaders’ meeting, said the White House will use the visit to announce the transfer of three C-130 aircraft and coastal patrol vessels to the Philippines, a new US trade mission focused on increasing American investment in the Philippines’ innovation economy, new educational programing and more.

Increased Chinese harassment of vessels in the South China Sea has added another dimension to the visit. On April 23, journalists from The Associated Press and other outlets were aboard the Philippine coast guard’s BRP Malapascua near Second Thomas Shoal when a Chinese coast guard ship blocked the Philippine patrol vessel steaming into the disputed shoal. The Philippines has filed more than 200 diplomatic protests against China since last year, at least 77 since Marcos took office in June.

State Department spokesperson Matthew Miller on Saturday called media reporting on the encounters a “stark reminder” of Chinese “harassment and intimidation of Philippine vessels as they undertake routine patrols within their exclusive economic zone.”

“We call upon Beijing to desist from its provocative and unsafe conduct,” Miller said.

US and Taiwanese officials have also been unnerved by recent critical comments by China’s ambassador to the Philippines, Huang Xilian, over the Philippines granting the US military increased access to bases.