Senior Trump administration officials were on Sunday scrambling to defend the president from escalating domestic and foreign policy scandals, ranging from impeachment proceedings in Washington to the US troop withdrawal in northern Syria.

Acting chief of staff Mick Mulvaney was forced to row back comments he made earlier in the week acknowledging the administration withheld military aid to Ukraine in order to elicit assistance investigating Donald Trump’s political opponents.

In a White House briefing on Thursday, Mulvaney listed “three issues” tied to the decision to withhold almost $400m in aid. These included “whether [Ukrainian officials] were cooperating in an ongoing investigation with our Department of Justice” related to the origins of the inquiry into Russian interference in 2016 election, which Mulvaney linked to an unfounded conspiracy theory which says Ukraine was involved in the theft of emails from Democratic servers.

Asked if that was tantamount to a quid pro quo, Mulvaney said: “We do that all the time with foreign policy.”

Speaking to Fox News Sunday, Mulvaney claimed his words had been misreported, stating he had not acknowledged a quid pro quo.

That’s what people are saying that I said, but I didn’t say that Mick Mulvaney

“That’s what people are saying that I said, but I didn’t say that,” he said.

But he had clearly changed his line, now stating there were only “two reasons” aid was withheld – “rampant corruption in Ukraine” and “whether or not other nations, specifically European nations, were helping with foreign aid to the Ukraine”.

The existence of a quid pro quo between Trump and Ukraine is at the centre of an impeachment inquiry led by Democrats in the House of Representatives.

The committees involved are also investigating Trump’s request that the Ukrainain government commence an investigation into Joe Biden and his son Hunter Biden. The president made the request during a 25 July phone call with his Ukrainian counterpart, Volodymyr Zelenskiy.

Mulvaney has denied that the Biden request was tied to the decision to withhold aid.

The acting chief of staff is under the spotlight in the impeachment inquiry after testimony from a state department official, George Kent, placed him at the centre of efforts to create a separate diplomatic channel to Ukraine staffed by Trump loyalists including outgoing energy secretary Rick Perry and Trump’s personal attorney Rudy Giuliani.

Democrats are weighing up whether to summon Mulvaney, according to reports.

Reports also emerged on Sunday that Mulvaney was facing ejection from his post before the impeachment inquiry began. CNN reported that Trump son-in-law Jared Kushner and other advisers began screening for new candidates last month.

Mulvaney, a former South Carolina congressman, is the third White House chief of staff under Trump although he retains the “acting” prefix. He said on Sunday he had not considered tendering his resignation this week.

“I’m very happy working there. Did I have the perfect press conference? No,” he said.

The Ukraine scandal is only one of a number in which the administration is currently embroiled.

On Saturday evening Trump was forced into an embarrassing climbdown, announcing his golf resort in Doral, Florida would no longer host the G7 summit next year following bi-partisan criticism of the decision.

At the end of the day he [Trump] still considers himself to be in the hospitality business Mick Mulvaney

In an attempt to defend the move, Mulvaney said: “At the end of the day he [Trump] still considers himself to be in the hospitality business.”

The administration is also reeling from bipartisan criticism of its decision to withdraw troops from northern Syria.

On Sunday, secretary of state Mike Pompeo sought to defend a fragile and brief ceasefire brokered with Turkey, which he described as “the outcome that President Trump sent us to achieve”.

The US and Turkey reached an agreement on Thursday to halt Turkish operations against Kurdish forces for five days to allow military and civilians to evacuate an area of land around the border about 20 miles deep, before the territory is claimed by Turkey.

An American soldier mounts the US flag on a vehicle near the town of Tel Tamr in northern Syria. Photograph: Baderkhan Ahmad/AP

Both sides have accused the other of violating the agreement. Republicans and Democrats in Washington argue the deal has undermined US interests in the region and delivered a significant victory to Turkish president Recep Tayyip Erdoğan.

Pompeo, also at the centre of the Ukraine scandal, distanced himself from such criticisms during an interview with ABC’s This Week, when asked if the Turkish government had been handed everything it had asked for.

“I was there. It sure didn’t feel that way when we were negotiating,” Pompeo said. “It was a hard-fought negotiation. It began before the vice-president and I even arrived in Ankara.”

Trump chimed in on Twitter, quoting his defense secretary on how “the ceasefire is holding up very nicely”. In his first version of the tweet, the president typed Mark Esper’s name as Mark Esperanto.

Later on Sunday he returned to the subject of impeachment, tweeting that the Ukraine whistleblower was a “fraud, just like the Russia Hoax”.

....fiction to Congress and the American People? I demand his deposition. He is a fraud, just like the Russia Hoax was, and the Ukraine Hoax is now. When do the Do Nothing Democrats pay a price for what they are doing to our Country, & when do the Republicans finally fight back? — Donald J. Trump (@realDonaldTrump) October 20, 2019

Over the weekend, Democratic House speaker Nancy Pelosi led a bipartisan delegation to Jordan to discuss the fallout of Trump’s troop withdrawal.

“Our bipartisan delegation is visiting Jordan at a critical time for the security and stability of the region,” Pelosi’s office said in a statement released on Saturday.

“With the deepening crisis in Syria after Turkey’s incursion, our delegation has engaged in vital discussions about the impact to regional stability, increased flow of refugees, and the dangerous opening that has been provided to Isis, Iran and Russia.”

Despite the chaos over US Syria policy, one of Trump’s most ardent supporters in the Senate seemed to have abandoned his previously stringent criticism.

Speaking to Fox News, Lindsey Graham said he was “increasingly optimistic that we can have some historic solutions in Syria that have eluded us for years if we play our cards right”.