US President Joe Biden arrived in Asia on Saturday vowing to urge Chinese leader Xi Jinping to rein in North Korea when they hold their first face-to-face meeting at next week's G20 summit.

President Biden met Southeast Asian leaders in Phnom Penh ahead of his encounter with his Chinese counterpart on Monday in Bali.

The meeting between the two powers comes after a record-breaking spate of missile tests by North Korea sent fears soaring that the reclusive state would soon conduct its seventh nuclear test.

In Monday's meeting on the sidelines of the G20 summit, Joe Biden will tell Xi Jinping that China -- Pyongyang's biggest ally -- has "an interest in playing a constructive role in restraining North Korea's worst tendencies", US National Security Advisor Jake Sullivan told reporters.

Joe Biden will also tell Xi Jinping that if North Korea's missile and nuclear build-up "keeps going down this road, it will simply mean further enhanced American military and security presence in the region".

Mr Sullivan said President Biden would not make demands on China but rather give Xi "his perspective".

This is that "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".

Whether China wants to increase pressure on North Korea is "of course up to them", Mr Sullivan said.

However, with North Korea rapidly ramping up its missile capacities, "the operational situation is more acute in the current moment", Mr Sullivan said.

Japanese Prime Minister Fumio Kishida added his voice to calls for concerted international action to halt Pyongyang's missile programme during talks with the Association of Southeast Asian Nations (ASEAN), China and South Korea.

Tokyo and Seoul have been increasingly alarmed by the North Korean testing blitz, which included an intercontinental ballistic missile.

South Korean President Yoon Suk-yeol's office said that, because of the rising tensions caused by the North's missile launches, he would hold a one-on-one summit with Kishida in Phnom Penh on Sunday.

Joe Biden and Xi Jinping, the leaders of the world's two biggest economies, have spoken by phone multiple times since Joe Biden became president in January 2021.

But the Covid-19 pandemic and Xi's subsequent aversion to foreign travel have prevented them from meeting in person.

Regional rivalry

The pair are not short of topics to discuss, with Washington and Beijing 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.

UN chief Antonio Guterres has urged the two sides to work together, warning Friday of "a growing risk that the global economy will be divided into two parts, led by the two biggest economies -- the United States and China".

Joe Biden met leaders from ASEAN on Saturday to push the US's commitment to the region, in a bid to counter Beijing's influence there.

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

President Biden said the United States wanted to work with ASEAN to "defend against the significant threats to rule based order and threats to the rule of law".

Xi emerges, Putin absent

Joe Biden and Xi Jinping both go into the G20 buoyed by recent domestic political success, President Biden's party having earned surprisingly strong midterm results and Xi Jinping having secured a landmark third term as China's leader.

At last month's Communist Party Congress, where he was anointed as chief again, Xi Jinping warned of a challenging geopolitical climate without mentioning the United States by name, as he wove a narrative of China's "inevitable" triumph over adversity.

The G20 summit will be the latest step in a diplomatic re-emergence for Xi after the pandemic -- it comes less than a fortnight after he hosted German Chancellor Olaf Scholz in Beijing.

As well as Joe Biden, Xi Jinping will also meet French President Emmanuel Macron before heading to Bangkok later in the week for the APEC summit.

Notably absent from the summit will be Russian President Vladimir Putin, who has been shunned by the West over his invasion of Ukraine, and who is instead sending Foreign Minister Sergei Lavrov.

Lavrov will press Moscow's view that the United States is "destabilising" the Asia-Pacific region with a confrontational approach, the Russian TASS news agency reported.

Ukrainian President Volodymyr Zelensky is expected to attend the G20 virtually, after his request to address the ASEAN gathering was turned down.