FILE PHOTO: U.S. Democratic presidential candidate and former U.S. Vice President Joe Biden responds to a question during a forum held by gun safety organizations the Giffords group and March For Our Lives in Las Vegas, Nevada, U.S. October 2, 2019. REUTERS/Steve Marcus

WASHINGTON (Reuters) - A spokeswoman for Joe Biden, a leading candidate seeking the 2020 Democratic presidential nomination, said on Thursday that U.S. President Donald Trump was “desperately clutching for conspiracy theories that have been debunked and dismissed by independent, credible news organizations.”

Hours earlier Trump told reporters that he wanted Ukraine and China to investigate Biden and his son, businessman Hunter Biden, a public request echoing the appeal he made in a phone call on July 25 with Ukrainian President Volodymyr Zelenskiy that led to an impeachment inquiry by the House of Representatives.

“Now, with his administration in free-fall, Donald Trump is flailing and melting down on national television,” Biden’s deputy campaign manager Kate Bedingfield said in a statement.