Vietnam and the Philippines warned of growing insecurity in Southeast Asia at a regional summit on Friday amid concerns that China was stepping up its activity in the disputed South China Sea during the coronavirus pandemic.
Both Hanoi and Manila lodged protests with China in April after Beijing unilaterally declared the creation of new administrative districts on islands in the troubled waterways to which Vietnam and the Philippines also have competing claims.
"Even as our region struggles to contain COVID-19, alarming incidents in the South China Sea occurred," Philippine President Rodrigo Duterte told an online meeting of Association of Southeast Asian Nations (ASEAN) leaders on Friday.
"We call on parties to refrain from escalating tensions and abide by responsibilities under international law," he said.
China has been pushing its presence in the Exclusive Economic Zones of other countries while claimants are preoccupied tackling the COVID-19 pandemic, prompting the United States to call on China to stop its "bullying behavior" there.
In early April, Vietnam said one of its fishing boats was sunk by a Chinese maritime surveillance vessel. China said that Vietnam's claims in South China sea are illegal and "doomed to fail".
In his opening remarks at the ASEAN Summit, Vietnamese Prime Minister Nguyen Xuan Phuc said international institutions and international law had been seriously challenged during the global crisis.
"The pandemic is fanning the flames of dormant challenges within the political, economic and social environment of the world and in each region," Phuc said.
"While the entire world is stretched thin in the fight against the pandemic, irresponsible acts and acts in violation of international law are still taking place, affecting the environment of security and stability in certain regions, including in our region," said Phuc, who made no mention of China in relation to the comments.