U.S. President Joe Biden has said that he believes China's ambition is to become the most powerful country in the world and vowed to stop it.

In his first White House press conference, Biden said that he and China's President Xi Jinping had spoken for nearly two hours after he succeeded Donald Trump as president.

China's goal, he said, is "to become the leading country in the world, the wealthiest country in the world and the most powerful country in the world," adding: "That's not going to happen on my watch."

Beijing has frequently dismissed claims that it is engaged in a global rivalry with other nations, pointing out that it is focused on improving the lives of its own citizens and collaborating to fight the global health pandemic.

Early this month, while addressing the relationship between China, the EU and the U.S., China's ambassador to the EU, Zhang Ming, noted that China "just eradicated extreme poverty. There is a lot more to be done to deliver a better life for the 1.4 billion Chinese people. China does not have the time and energy or interest to be anyone's rival."

Asked about his own attitude to China, President Biden said that he knew Xi well from his days as vice president and had told him the U.S. was not looking for confrontation, but would insist that China play by international rules for fair competition and fair trade. Biden said he and Xi understood each other's positions well. 

Biden also said that he was not anti-China, but wanted to talk with allies "to hold China accountable to follow the rules," adding that the U.S. would continue to draw attention to where it thought China "continues to completely violate human rights."

China has repeatedly rebutted claims that its policies in Xinjiang violate human rights. Measures taken in the region are designed to combat terrorism and increase prosperity for everyone living there, Beijing says. 

At the United Nations Human Rights Council last month, China's Ambassador Chen Xu said those seeking to criticize should instead focus on problems within their own borders, such as discrimination, social injustice and treatment of refugees.

The U.S. president spent the bulk of his press conference defending his administration's border policies as reporters highlighted the plight of families trapped in overcrowded immigration centers. He faced accusations of encouraging families to send their children on dangerous journeys across inhospitable terrain and then failing to ensure their welfare when they arrived.

On the coronavirus pandemic, he said he would double his vaccination target. He also suggested he would stand for re-election when his current four-year term as president ends.