US President Donald Trump, already facing an impeachment inquiry after urging Ukraine to investigate his political rival Joe Biden, has now urged China to do likewise.
He said both China and Ukraine should look into Mr Biden, a Democratic presidential frontrunner, and his son.
"China should start an investigation into the Bidens," said Mr Trump.
The Democrats accuse Mr Trump of dangling military aid as a way to press Ukraine to dig dirt on Mr Biden.
A 25 July phone call between Mr Trump and Ukrainian President Volodymyr Zelensky triggered an intelligence community whistleblower complaint and the impeachment inquiry.
But Mr Trump said on Thursday that the inquiry, which could culminate in a congressional attempt to remove him from office, is "crap".
BBC
Russia's unmanned Luna-25 spacecraft has crashed into the Moon after spinning out of control, officials say.
Donald Trump has confirmed that he will not take part in Republican presidential debates with his rivals in the race for the White House.