US, Russia hostility
Despite disagreements, tensions over the past year have markedly eased between China and the United States, with President Joe Biden supporting dialogue to reduce the potential for conflict.
Biden and his political heir Vice President Kamala Harris, who both skipped the summit ahead of elections, have taken a different approach to Russia, believing Moscow's diplomatic overtures are insincere.
Blinken and Russian Foreign Minister Sergei Lavrov were spaced apart by the leaders of South Korea and India at the summit. Blinken said he did not speak to Lavrov but that neither walked out when the other addressed the summit.
"I think it's safe to say that we heard each other. I didn't hear anything new, unfortunately, about the ongoing Russian aggression against Ukraine," Blinken said.
Lavrov told reporters that the United States was "destructive" in Asia.
He also attacked the "militarisation" of Japan, where security-minded new Prime Minister Shigeru Ishiba has in the past called for a NATO-style Asian pact with an unstated goal of deterring China.
"The Japanese are obviously being pushed to such a course by the United States," Lavrov charged.
Japan's foreign ministry said that Ishiba, on his first foreign trip since taking over, reiterated "serious concerns" about the "intensification of Chinese military activities in areas surrounding Japan" in a meeting with Premier Li Qiang.
Li made a veiled swipe at Ishiba during an ASEAN-related meeting on Thursday, warning of the danger of "attempts to introduce bloc confrontation and geopolitical conflicts into Asia".
In an interview with AFP at the summit, EU chief Charles Michel called for disputes to be resolved "through peaceful means" in the South China Sea.
Push for Myanmar diplomacy
The summit saw participation for the first time in more than three years by military-run Myanmar, which has brushed aside a 2021 ASEAN plan after its coup that calls for dialogue and an immediate end to violence.
ASEAN leaders in a statement voiced "deep concern" over Myanmar's path and stood by the plan, known as the Five-Point Consensus.
The United States, while supporting ASEAN diplomacy, has urged no let-up in pressure against the junta until it shows signs of progress.
Indian Prime Minister Narendra Modi, who has engaged the junta in the neighbouring country, voiced support for the restoration of democracy but said: "We believe that Myanmar should be engaged rather than isolated in this process."
Modi, who was seen speaking warmly with Blinken, has annoyed Washington by refusing to back Western sanctions on Russia, India's Cold War partner.
India, by contrast, has a border dispute with China and Modi at the summit voiced firm support for open navigation in the South China Sea.