Leaders of 18 Asia-Pacific countries began a meeting in Laos on Friday to discuss issues ranging from Russia's prolonged war in Ukraine, North Korea's nuclear and missile development, and the expanding conflict in the Middle East.

The East Asia Summit involving the 10-member Association of Southeast Asian Nations as well as such countries as Japan, China, India, the United States and Russia will also likely take up mounting tensions in the South China Sea, where several ASEAN members are engaged in territorial rows with Beijing.

The U.S. State Department has warned of China's "escalatory and irresponsible steps designed to coerce and pressure" smaller countries with overlapping territorial claims in the South China Sea.

Participants from the 18 countries at the meeting in Vientiane include new Japanese Prime Minister Shigeru Ishiba, Chinese Premier Li Qiang, U.S. Secretary of State Antony Blinken and Russian Foreign Minister Sergey Lavrov.

The rift between Western nations and China and Russia has been widening over Beijing's expanding military activities in the East and South China seas and the war in Ukraine launched by Moscow in February 2022.

Washington claims China is supporting the Russian defense industrial base and has urged Beijing to desist.

The EAS comprises ASEAN -- which groups Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam -- plus Australia, China, India, Japan, New Zealand, Russia, South Korea and the United States.