President Trump's phone conversations with world leaders often vexed and alarmed members of his own staff.

Details of discussions Trump had with Russian President Vladimir Putin, Chinese President Xi Jinping, and others were described in a Washington Post report published on Friday, showing the U.S. president expressing deference to authoritarian leaders and taking a severe tone with allies, such as former British Prime Minister Theresa May.

The revelations come as intense scrutiny is being placed on a July 25 phone call, in which Trump urged Ukrainian President Volodymyr Zelensky to investigate a matter related to political rival Joe Biden, and an intelligence officer's whistleblower complaint that raised concerns about an alleged effort to conceal details of that private conversation and others using a highly secure computer system. These revelations led to House Democrats engaging in an impeachment inquiry against Trump.

“There was a constant undercurrent in the Trump administration of [senior staff] who were genuinely horrified by the things they saw that were happening on these calls,” said one former White House official. “Phone calls that were embarrassing, huge mistakes he made, months and months of work that were upended by one impulsive tweet.”

One phone call Trump had with Putin weeks after he was inaugurated was described as "obsequious" and "fawning" by a former White House official. In that Jan. 28, 2017 conversation, Trump said Putin, who ordered the Russian interference campaign into the 2016 election, was a great leader and apologized for not calling sooner.

“He was like, ‘Oh my gosh, my people didn’t tell me you wanted to talk to me,’” one source familiar with the call said.

In another call, Trump told a Saudi royal he would support allowing Saudi Arabia into the Group of Seven, which has not happened. But it indicated a pattern, as Trump has publicly floated the idea of readmitting Russia to the alliance of the world’s seven largest economies, insisting the only reason Russia was booted from the group is that Putin “outsmarted” President Barack Obama in annexing Crimea.

Trump took on a much harsher tone in talking with May in the summer of 2018. He complained about the United Kingdom's contribution to NATO and disputed the conclusion by British intelligence that the Kremlin was behind the poisoning in England of Sergei Skripal, a former Russian intelligence officer who worked as a British double agent, and his daughter by Novichok with a Russian-developed nerve agent.

“Trump was totally bought into the idea there was credible doubt about the poisoning,” a source said. “A solid 10 minutes of the conversation is spent with May saying it’s highly likely and him saying he’s not sure.”

Another source of anxiety for staff was Trump's propensity to stray off topic and their attempts to temper this behavior, with minimal success, by handing him notes. For instance, in one call with Xi, a former official said Trump repeatedly brought up how much he liked chocolate cake.

In what appears to be an effort to crack down on leaks, Trump last week ordered a reduction in size of the National Security Council after it was reported the whistleblower who filed the complaint about his Ukraine call was a CIA official who was at one point assigned to the White House.