US President Joe Biden and China's Xi Jinping opened a virtual summit Monday with an appeal for better communication between the superpowers and "guardrails" to avoid conflict.

Speaking from the White House to Xi on a television screen, Biden said they must develop "guardrails" to "ensure that the competition between our countries does not veer into conflict, whether intended or unintended."

He said they would have a "candid" discussion.

Activists campaign against human rights violations in China in Washington in November 2021
Activists campaign against human rights violations in China in Washington in November 2021 AFP / Nicholas Kamm

Xi, speaking from Beijing, called Biden "my old friend," but said the rivals must work more closely.

"China and the United States need to increase communication and cooperation," he said.

The two leaders have spoken by phone twice since Biden's inauguration in January but with Xi refusing to travel abroad because of the pandemic, an online video meeting was the only option short of an in-person summit.

At a virtual summit with China's Xi Jinping on Monday, Biden wants to avoid any "misunderstanding" in bilateral ties
At a virtual summit with China's Xi Jinping on Monday, Biden wants to avoid any "misunderstanding" in bilateral ties AFP / NICOLAS ASFOURI

White House spokeswoman Jen Psaki said Biden was going into the summit, expected to last a couple of hours, "from a position of strength," after months of rebuilding alliances with other democracies to contain China.

The meeting is "an opportunity to set the terms of the competition with China" and to insist the leadership in Beijing "play by the rules of the road," Psaki said.

Most of the attention in the build-up to the meeting has focused on the sparring over Taiwan, a self-ruling democracy claimed by China. Biden's aides have cast the summit as an opportunity to help prevent tensions from escalating.

Biden will "make clear that we want to build common guardrails to avoid miscalculation," a senior US administration official, speaking on condition of anonymity, told reporters.

Activists campaign against human rights violations in China in Washington in November 2021
Activists campaign against human rights violations in China in Washington in November 2021 AFP / Nicholas Kamm

However, the White House sought to temper expectations, with the official saying that the summit "is not a meeting where we expect deliverables to be coming out."

Biden, a veteran of foreign policy issues during his decades in politics, has often said phone conversations are no substitute for face-to-face meetings.

Xi has not left China for nearly two years, and Biden sharply criticized his absence at the recent COP26 climate summit in Glasgow and G20 summit in Rome.

This file handout photo from February 2020 shows a Taiwanese F-16 fighter jet flying next to a Chinese H-6 bomber
This file handout photo from February 2020 shows a Taiwanese F-16 fighter jet flying next to a Chinese H-6 bomber Taiwan's Defence Ministry / Handout

Relations between the superpowers plummeted during the presidency of Donald Trump, who launched a trade war with China while assailing Beijing's response to an international probe into the origins of the Covid pandemic in the Chinese city of Wuhan.

Biden has recast the confrontation more broadly as a struggle between democracy and autocracy.

He got a boost on Monday when he signed into law a $1.2 trillion infrastructure package, the biggest of its kind in more than half a century. Biden describes the initiative as an important step in catching up with years of intensive Chinese government investments, thereby proving that democracies can compete.

"The world is changing," he said. "We have to be ready."

While the day-to-day tone is more measured than in the Trump era, tension over Taiwan is threatening to escalate into dangerous new territory.

China has ramped up military activities near Taiwan in recent years, with a record number of warplanes intruding into the island's air defense zone in October.

The United States says it supports Taiwan's self-defense but is ambiguous about whether it would intervene to help directly.

"Any connivance of and support for the 'Taiwan independence' forces undermines peace across the Taiwan Strait and would only boomerang in the end," Chinese Foreign Minister Wang Yi told US Secretary of State Antony Blinken in a telephone call heading into the weekend.

And China's foreign ministry on Monday put the onus on Biden to improve relations.

"We hope that the US will work in the same direction as China to get along with each other," foreign ministry spokesman Zhao Lijian told reporters.

The US administration official signaled Biden would be "very direct" on what he called "China's coercive and provocative behavior with respect to Taiwan."

But the official also stressed that the two nations had room for cooperation in various areas, such as climate change.