U.S. Secretary of State Antony Blinken heads to the Philippines next week, following a recent trade mission there by U.S. Commerce Secretary Gina Raimondo. The visit comes amid escalating tensions between the Philippines and China over maritime disputes in the South China Sea.

“Secretary Blinken will travel to Manila to reaffirm our unwavering commitment to our Philippine allies” and “promote peace and stability in the South China Sea,” State Department spokesperson Matthew Miller said during a Thursday briefing.

Philippine President Ferdinand Marcos Jr. has announced his meeting with Blinken on March 19, with a focus on issues of cooperation and security.

“The secretary’s visit will also underscore the importance of our strong bilateral ties, which for 75 years, have been critical to advancing our shared vision for a free and open connected, prosperous, secure and resilient Indo-Pacific region,” Miller said.

During Commerce Secretary Raimondo’s trade and investment mission to Manila this week, she announced plans to invest more than $1 billion in the Philippines’ tech sector and help double the number of semiconductor factories in the country. Washington’s move is seen as boosting Manila’s chip sector amid intense competition with Beijing.

Blinken will start his trip late Thursday, heading first to Vienna for a meeting of the United Nations Commission on Narcotic Drugs. His trip will include a stop in Seoul where South Korea is hosting a Summit for Democracy.

The meeting between Marcos and Blinken is set against a backdrop of increasing tension over territorial disputes in the South China Sea between Manila and Beijing. Marcos has committed to upholding the Philippines’ maritime claims, following Chinese President Xi Jinping’s call for military preparedness for potential sea conflicts.

A recent collision near the waters around Second Thomas Shoal (known as Ren’ai Shoal in China) has further strained the relationship between the two countries. The rich fishing ground is about 200 kilometers (124 miles) from the nearest Philippines island and 1,500 kilometers (932 miles) from China.

On March 5, the Philippine Coast Guard said Chinese ships carried out dangerous maneuvers and fired water cannons on Philippine vessels, causing multiple collisions, and damaging at least one Philippine vessel.

China accused the Philippines of intruding on its territory “without the permission of the Chinese government.” A PRC spokesperson said the Chinese foreign ministry “has lodged solemn representations with the Philippines and expressed strong protest.”

According to an international tribunal’s legally binding decision issued in July 2016, Second Thomas Shoal is located within the exclusive economic zone of the Philippines, and China has no lawful maritime claims to the waters around the low-tide feature.

Beijing has rejected the ruling, claiming “indisputable sovereignty” over most of the South China Sea.

The United States said it stands with the Philippines. The State Department issued a strong statement on March 5 to condemn “the PRC’s repeated obstruction of Philippine vessels” and said Beijing’s actions “show disregard for the safety and livelihoods of Filipinos and international law.”

The White House has announced that it will host Japanese Prime Minister Kishida Fumio for an official visit on April 10. Japanese media outlet The Asahi Shimbun reported that leaders from Japan, the United States and the Philippines are planning a summit in Washington around that time.