Trump 's telephone habits with other world leaders are coming under scrutiny

President Donald Trump's telephone habits with other world leaders are coming under scrutiny in the wake of his request for the Ukraine to investigate political rival Joe Biden.

In one call with Saudi officials, Trump vowed that he would help the theocratic country join the G7 group of leading industrial democracies, according to the Washington Post.

In another call, he reportedly set aides scrambling by casually promising the president of Peru that he would send a C-130 Hercules military transport plane within 24 hours.

'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,' one unnamed former White House official told the Post.

Saudi Arabia's Crown Prince Mohammed bin Salman is seen in a file photo. Trump reportedly promised to get the theocratic monarchy into the G7

'Phone calls that were embarrassing, huge mistakes he made, months and months of work that were upended by one impulsive tweet.'

The report also details two of Trump's calls with Russian President Vladimir Putin, claiming that Trump warmly praised the authoritarian leader in one of the first calls of his presidency, and later called to quiz Putin on advice for forging a relationship with North Korean leader Kim Jong Un.

It comes as Trump's July 25 call with Ukrainian president Volodymyr Zelensky continues to fuel a political firestorm, with an impeachment inquiry probing Trump's request that the Ukraine investigate possible corruption involving Biden's son.

Trump is seething over an impeachment inquiry into his conduct after Democrats subpoenaed the White House about contacts with Ukraine and he signaled his administration would not cooperate.

A U.S. Air Force C-130 Hercules cargo plane is seen in a file photo. Trump reportedly promised to deliver one like it to Peru overnight, sending aides scrambling

In a series of tweets Saturday sent as the presidential motorcade ferried him to his Virginia golf course, Trump defended his comments and lashed out at critics, including a past foil, Sen. Mitt Romney, R-Utah.

'This is a fraud against the American people!' he tweeted.

The inquiry reached deeper into the White House when the House sent a letter Friday to Trump's acting chief of staff, Mick Mulvaney, informing him that the White House was being subpoenaed for documents it had refused to produce. The move capped a tumultuous week that widened the constitutional battle between the executive branch and Congress and heightened the political standoff with more witnesses, testimony and documents to come.

Trump received support from Secretary of State Mike Pompeo, who dismissed questions about Trump's attempts to push Ukraine and China to investigate Democratic rival Joe Biden as a 'silly gotcha game.'

'The president has every right to have these set of conversations,' Pompeo told reporters while traveling in Greece. He insisted the administration's foreign efforts were reasonable, responsible and necessary to target graft, ensure aid is spent properly and protect American democracy.