US President Joe Biden said Sunday he will seek to establish "red lines" in America's fraught relations with Beijing when he holds high-stakes talks with Chinese counterpart Xi Jinping. 

Biden said he goes into Monday's encounter on the sidelines of a G20 summit in Indonesia stronger after his Democratic Party's unexpected success in midterm elections they were forecast to lose heavily.

Washington and Beijing are at loggerheads over issues ranging from trade to human rights in China's Xinjiang region and the status of the self-ruled island of Taiwan. Biden said he expected candid talks with Xi.

"I know Xi Jinping, he knows me," he added, saying they have always had "straightforward discussions".

The two men have known each for more than a decade, since Biden's time as vice-president, but Monday will see them meet face-to-face for the first time in their current roles.

"We have very little misunderstanding. We just got to figure out what the red lines are," Biden said.

White House officials say Biden will push China to use its influence to rein in North Korea after a record-breaking spate of missile tests sent fears soaring that the reclusive regime will soon carry out its seventh nuclear test.

Biden had a fillip overnight with the news that the Democrats retained their effective majority in the US Senate thanks to Catherine Cortez Masto winning in Nevada.

"I know I'm coming in stronger," he said of the midterms' impact on his talks with Xi.

Japan, South Korea talks

Biden will meet his South Korean counterpart Yoon Suk-yeol and Japanese Prime Minister Fumio Kishida on Sunday to discuss ways to address the threat posed by the North's missile programme.

China is Pyongyang's main ally and US officials say that, while Biden will not make demands, he will warn Xi that further missile and nuclear build-up would mean the United States boosting its military presence in the region — something Beijing bitterly opposes.

"North Korea represents a threat not just to the United States, not just to (South Korea) and Japan but to peace and stability across the entire region," US National Security Advisor Jake Sullivan told reporters.

Kim Jong Un's regime ramped up missile launches in response to large-scale US-South Korean air exercises, which the North described as "aggressive and provocative".

Biden on Sunday held talks with Prime Minister Anthony Albanese of Australia, a key regional ally and member of the Quad security group.

Beijing has denounced the Quad, which also includes the United States, Japan and India, as an attempt to isolate it.

Diplomatic blitz

Biden flew to Phnom Penh from the COP27 climate conference as part of US efforts to boost its influence in Southeast Asia as a counter to China.

China has been flexing its muscles — through trade, diplomacy and military clout -- in recent years in a region it sees as its strategic backyard.

Biden told leaders at an East Asia Summit — including Chinese Premier Li Keqiang — on Sunday that the United States would speak out against Beijing's rights abuses, according to a White House press release.

A day earlier Biden took a veiled swipe at Beijing in talks with leaders from the Association of Southeast Asian Nations (ASEAN) regional bloc.

He said the United States would work with ASEAN to "defend against the significant threats to rules-based order and threats to the rule of law".

While the president did not refer to China by name, Washington has long criticised what it says are Beijing's efforts to undermine international norms on everything from intellectual property to human rights.

Despite the US-China tensions the pair clinked glasses together in a toast at a gala dinner Saturday night, where they were seated on either side of the host, Cambodian leader Hun Sen.

While Biden goes into the meeting with Xi buoyed by the Democrats seeing off a predicted Republican "red wave", Xi was anointed last month for a historic third term as paramount leader by the Chinese Communist Party congress.

Li met International Monetary Fund chief Kristalina Georgieva at the ASEAN gathering on Saturday, when he also addressed participants.

Biden and Li took part Sunday in an East Asia Summit that rounds off the first leg of a trilogy of top gatherings in the region, with the G20 on the holiday island of Bali and an APEC gathering in Bangkok to follow.

The consequences of the war in Ukraine are set to dominate the upcoming talks, although Russian President Vladimir Putin will be notably absent.

(AFP)