Sen. Lisa Murkowski (R-Alaska) pushed back on the idea endorsed by the Trump administration this week that withholding foreign aid to other countries for political purposes is a routine and appropriate way of doing business.

“You don’t hold up foreign aid that we had previously appropriated for a political initiative,” Murkowski, a senior appropriator, told reporters on Capitol Hill Thursday afternoon. “Period.”

During a stunning press conference earlier that day, acting White House chief of staff Mick Mulvaney acknowledged for the first time that President Donald Trump withheld foreign aid in order to get Ukraine’s help in a political probe.

“We do that all the time with foreign policy,” Mulvaney said at the White House.

“Get over it,” he added later. “There is going to be political influence in foreign policy.”

Mulvaney said that the Trump administration was withholding aid from Ukraine to pressure its government into investigating the Democratic National Committee’s server and alleged corruption in the 2016 election ― not Trump’s political rival former Vice President Joe Biden. Nevertheless, his comments appear to acknowledge that a “quid pro quo” did occur with respect to aid to Ukraine, despite many Republicans and Trump allies insisting otherwise.

The House of Representatives launched a formal impeachment inquiry last month following a whistleblower complaint concerning a July phone call in which Trump repeatedly urged Ukraine’s president to initiate an investigation into Biden and his son Hunter. Trump did so while holding up U.S. military aid to Ukraine.

Gordon Sondland, the U.S. ambassador to the European Union, also broke with Trump on Thursday, telling House impeachment investigators that he was “disappointed” in the president’s efforts to have his lawyer, Rudy Giuliani, interfere in foreign affairs. Sondland also testified that Giuliani sought to link to a White House visit for Ukraine’s newly elected president to demands that Ukraine prioritize investigations targeting Trump’s political rivals, including the Bidens.

“Withholding foreign aid in order to pressure a foreign government to take such steps would be wrong,” Sondland said in prepared testimony. “I did not and would not ever participate in such undertakings.”