MANILA (Reuters) - Chinese President Xi Jinping has promised his Philippine counterpart that China would not build structures on a rocky outcrop both countries claim in the South China Sea, a Philippine government minister said on Thursday.

China's President Xi Jinping attends a welcoming ceremony for Italian President Sergio Mattarella (not in picture) at the Great Hall of the People in Beijing, China February 22, 2017. REUTERS/Jason Lee

Strained ties between the two countries have improved since President Rodrigo Duterte took power in the Philippines in June and began a shift away from traditional ally the United States towards closer relations with China.

China has alarmed some of its neighbors and raised concern in the United States by constructing seven artificial islands on reefs in the South China Sea’s Spratly islands, some equipped with air and port facilities for suspected military use.

China denies any hostile intent and says it will maintain freedom of navigation.

Philippine Foreign Minister Perfecto Yasay said Xi’s pledge was made during a meeting with Duterte in Beijing in October, after the Philippines raised the issue of the disputed shoal in response to U.S. intelligence reports suggesting China was sending dredging ships to the area.

“President Xi has promised President Duterte they will not reclaim and build structures on Scarborough Shoal,” Yasay told reporters.

The shoal is northeast of the Spratly islands. China seized it in 2012 and denied Philippine fishermen access.

Yasay was responding to a query about a Reuters report that China was close to completing structures on its manmade islets in the Spratlys that appear designed to house long-range surface-to-air missiles.

China allowed Philippine fishermen to return to the Scarborough Shoal after Duterte’s visit.

Yasay said it would be a “game changer” if China broke its promise not to build on the shoal, adding he was confident it would not.

The Philippines would file another protest if it could confirm China was completing missile sites on its manmade islands, he added.

China found Yasay’s remarks “baffling and regrettable”, and they “do not accord” with the development of China-Philippines relations or the overall stable situation in the South China Sea, a foreign ministry spokesman said.

“We hope Mr Yasay can adhere to the consensus reached by the two countries’ heads of state and the common wishes of regional countries, and can speak and act cautiously,” the spokesman, Geng Shuang, told a regular briefing.

China started reclaiming the seven features in the Spratly islands immediately after the Philippines filed an arbitration case in the Hague in 2013, questioning its claims to almost the entire South China Sea.

The Philippines won the case in July but Duterte has said he wanted to avoid confrontation with China and saw no need to press it to abide by the ruling.

Brunei, Malaysia, the Philippines, Taiwan and Vietnam also have claims in the strategic waterway, through which about $5 trillion worth of ship-borne goods pass every year. It is also believed to be rich in oil and gas.