US President Joe Biden and Chinese leader Xi Jinping had "candid" phone calls on Thursday, with Mr Xi warning the US leader not to "play with fire" on Taiwan, Chinese state media reported.
The online meeting lasting more than two hours as Beijing and Washington increasingly risk open conflict over the island, which China claims as part of its territory.
"Those who play with fire will eventually get burnt," Mr Xi was quoted as telling Mr Biden, state-run news agency Xinhua reported.
The Chinese president used the same language when he spoke with Mr Biden last November.
"I hope the US side fully understands that," Mr Xi said.
"It is the firm will of the over 1.4 billion Chinese people to firmly safeguard China's national sovereignty and territorial integrity."
Despite the tense exchange over Taiwan, the two leaders agreed to schedule what would be their first meeting in person since Mr Biden took office, a US official said.
They "discussed the value of meeting face-to-face and agreed to have their teams follow up to find a mutually agreeable time to do so", the official said.
The call, the fifth between the two leaders, came as concerns grow over a possible visit to Taiwan by House Speaker Nancy Pelosi.
The White House said Mr Biden stressed that US policy on Taiwan "has not changed and that the United States strongly opposes unilateral efforts to change the status quo or undermine peace and stability across the Taiwan Strait".
It said the call was a part of the Biden administration’s efforts to "maintain and deepen lines of communication" with China and "responsibly manage our differences and work together where our interests align", such as climate change and health.
It had earlier said the two leaders would discuss the war in Ukraine.
“This is about keeping the lines of communication open with the president of China, one of the most consequential bilateral relationships that we have, not just in that region, but around the world, because it touches so much,” National Security Council spokesman John Kirby said on Wednesday.
Mr Biden wants to find new ways to work with China and contain its influence around the world.
But differing perspectives on global health, economic policy and human rights have long tested the relationship, with China’s refusal to condemn Russia’s invasion of Ukraine adding more strain.
Beijing has issued increased threats over Ms Pelosi's possible visit Taiwan.
Mr Kirby said the White House would provide her with “all the context” she needs about making a decision on the visit, but that an announcement on the trip had not yet been made.
The White House had said this week that Ms Pelosi's potential trip to the island would not be a topic of discussion during the call, as there is “no trip to speak to at this time”.
Under the “one China” policy, the US does not have diplomatic relations with Taiwan and recognises Beijing as China's government, but it does supply military equipment for the island's defence.
The US repeated that the policy has not changed despite speculation over Ms Pelosi's possible trip.
Mr Biden had also planned to discuss climate and economic issues, and placing a price cap on Russian oil to punish the Kremlin for its invasion of Ukraine, Reuters reported.
“China’s aggressive course of behaviour in the Indo-Pacific” would also be a topic of discussion between the two leaders, Mr Kirby said before the meeting.
Agencies contributed to this report
