President Donald Trump on Friday accused a witness in the Democratic-led impeachment inquiry of lying and offered an explanation for his controversial use of his personal lawyer Rudy Giuliani on Ukraine policy, saying Giuliani’s crime-fighting abilities were needed to deal with a corrupt country.

Trump made his remarks the day after the fifth and final scheduled day of public hearings in the U.S. House of Representatives inquiry, which threatens his presidency even as he seeks re-election in November 2020.

The Republican president took issue with testimony on Thursday by David Holmes, a U.S. embassy official in Ukraine. Holmes said under oath that at a Kiev restaurant he overheard a July 26 cellphone conversation in which Trump loudly pressed Gordon Sondland, the U.S. ambassador to the European Union, for details on whether Ukraine would carry out politically motivated investigations the president was seeking.

“I guarantee you that never took place,” Trump told Fox News Channel’s “Fox & Friends” program.

“That was a total phony deal,” he added.

Trump appointed Sondland to the envoy post after the wealthy Oregon hotelier donated $1 million to his inaugural committee. While Sondland in testimony described an easygoing relationship between the two, Trump said on Friday he had spoken with him “a few times,” adding, “I hardly know him, OK?”

In another development, Trump’s former national security adviser John Bolton said that Twitter Inc (TWTR.N) had returned control to him of his personal account. He accused the White House of blocking his access to it after he left his post in September.

In a post on the account, Bolton asked whether the White House had done so “out of fear of what I may say?” A person close to Bolton told Reuters there were numerous requests made to the White House on Bolton’s behalf to stop blocking his access before going to the company to regain control.

Bolton so far has declined to cooperate in the impeachment inquiry.

Trump, a prolific Twitter user, denied in the Fox interview that Bolton’s access had been blocked by the White House.

Twitter did not immediately respond to a request for comment.

Testimony at the hearings put a spotlight on Trump’s decision to give Giuliani, a private citizen with no formal job in his administration, an outsized role to shape American policy toward Ukraine rather than using the U.S. government’s usual diplomatic and national security channels.

Bolton is among the various US officials described as being alarmed at Giuliani’s actions, including pushing Ukraine to conduct two investigations that could harm Trump’s political adversaries. Former White House Russia expert Fiona Hill recalled how Bolton called Giuliani “a hand grenade who’s going to blow everybody up.”

During the hearings, current and former White House officials and diplomats voiced alarm at Giuliani’s activities.