U.S. President Donald Trump has accused China of meddling in the 2020 election, claiming he possesses declassified intelligence files showing Beijing helped former President Joe Biden win.

In a primetime address at the White House on Thursday, Mr Trump said Beijing carried out “the largest compromise of election data in history.”

The president said the files corroborated his claims of China’s interference to favour Mr Biden and uncovered “shocking vulnerabilities” in the country’s voting systems.

He said China made an “illicit acquisition” of U.S. voter files, including personal information, before the election. He also claimed data from 18 states was “bought, stolen, or hacked by China.”

Mr Trump said “those responsible for sounding the alarm” did not disclose their findings to government officials or Congress, adding that he ordered the Department of Justice to investigate Beijing’s alleged interference.

The president also claimed U.S. voting machines were “extremely exposed” to external interference, particularly from Russia, China, and Iran.

However, he did not provide evidence to support his claims that China obtained information to interfere in the election.

“America is back and doing really well, but we still have a major challenge that must be urgently addressed because no country can be great without fair and honest elections; you have to trust your country,” Mr Trump said in the 24-minute speech.

He added, “Because if there can be no trust, there can be no greatness, and that’s very simple: no trust, no greatness.”

Mr Trump has repeatedly claimed that the election was stolen from him. However, court rulings and U.S. intelligence assessments found no evidence of election fraud or foreign interference altering the vote outcome.

In 2021, the U.S. National Intelligence Council said, “China did not deploy interference efforts and considered but did not deploy influence efforts intended to change the outcome of the U.S. presidential election.”

Responding to Mr Trump’s claims, China’s foreign ministry spokesman Lin Jian said they were “entirely fabricated” and are “malicious smears” that have “long been proven to be groundless.”

Mr Trump’s claim came after a new poll from the Washington Post-Ipsos showed his approval rating declined to 37 per cent.

The president also urged Congress to pass the Save America Act, which would require proof of citizenship and a photo ID for voter registration.