President Donald Trump and Secretary of State Marco Rubio are considering whether to fire U.S. Ambassador to Greece Kimberly Guilfoyle after a series of published reports detailing allegations of improper and potentially illegal conduct before and during her diplomatic tenure in Athens.

According to a senior U.S. official speaking on Sunday, both Trump and Rubio are “extremely pissed off” by the reported misconduct and are expected to decide her future this week, after the Monday holiday for Columbus Day.

The official, who asked to remain anonymous to discuss internal deliberations, said Rubio was particularly incensed. His anger was heightened by the fact that he visited Athens just last week, when Guilfoyle welcomed him with a bear hug and participated in most, if not all, of his scheduled public events while the allegations were circulating.

In a series of investigative reports, The Wall Street Journal detailed multiple instances of questionable conduct attributed to Guilfoyle.

The allegations include an implied threat to a foreign official in the host country, accepting improper gifts and services, and offering to leverage her political influence within the administration in exchange for paying a substantial credit card bill.

Guilfoyle has not directly addressed the reports in person, but her legal team issued a statement late Sunday denying any wrongdoing.

Her lawyers claimed the funds she requested from a prominent Trump donor were intended as payment for public appearances and speaking engagements completed before her ambassadorial nomination that had gone unpaid.

Her attorneys, David Schwartz and Jesse Binnall, likewise dismissed allegations surrounding her travel on private aircraft, stating that before every such flight she “sought, obtained and followed State Department guidance and followed the Department’s travel regulations,” they said.

“Ambassador Guilfoyle has served, and will continue to serve, with integrity, honor and distinction. We are evaluating all available legal remedies to collect this debt and any other potential causes of action,” the lawyers said.

After initially defending Guilfoyle when the first report appeared, Rubio has since refrained from publicly addressing the mounting accusations. On Wednesday, Rubio said: “Our ambassador has been a strong ambassador here.”

However, after a subsequent report was published late Wednesday, Rubio confronted reporters on Thursday prior to departing Athens. He berated journalists for pressing him on the allegations, saying he did not know whether they were accurate and would not respond without independent confirmation.

“You guys walk around thinking that because some source told you something and you reported it, it’s the gospel. It’s not the gospel. It’s not the gospel for me. That’s not the way we do things,” Rubio said at the foot of his plane as Guilfoyle, who was present to see him off, looked on.

The official noted that Rubio’s frustration grew significantly as the published reports multiplied.

A second U.S. official, also speaking on condition of anonymity to discuss sensitive personnel matters, said the State Department’s inspector general is examining the claims, which first appeared in the Journal late last month and have since expanded.

The second official could not confirm whether a formal IG investigation had been launched. Inspectors general regularly perform informal inquiries into complaints involving agency personnel, and many of these preliminary reviews do not progress to full-scale investigations, which can ultimately lead to disciplinary measures up to and including dismissal.

The State Department has declined to comment on a potential IG investigation.

Top congressional Democrats on key foreign relations panels have already called for a formal investigation into Guilfoyle.

The calls have come from Rep. Gregory Meeks of New York and Sen. Jeanne Shaheen of New Hampshire—the leading Democrats on the House Foreign Affairs and Senate Foreign Relations committees—as well as Rep. Robert Garcia, D-Calif., the ranking member on the House Committee for Oversight and Government Reform.

Since late September, the Journal has published several accounts outlining questionable behavior. Its initial report alleged that Guilfoyle told reception guests the U.S. could undermine the Greek government if it chose to, while also promoting the commercial interests of a specific Greek construction and energy firm and allowing its lobbyist to attend private diplomatic meetings.

During Rubio’s stay in Athens, the Journal published text messages indicating Guilfoyle had asked a Trump donor and supporter to settle a $100,000 credit card bill shortly before her confirmation hearing, offering access to key administration officials if he agreed.

The Journal also reported that Guilfoyle was enraged over being excluded from a Greek-themed event at the World Economic Forum in Davos, Switzerland, earlier this year, demanding to attend while boasting about luxury travel to France alongside energy-sector executives.

A separate report from the British tabloid The Daily Mail claimed that Guilfoyle had alienated personnel at the U.S. Embassy in Athens and pushed the boundaries of behavior appropriate for the chief representative of the U.S. government to Greece.

Guilfoyle is a former California prosecutor and a Fox News host who was previously engaged to Trump’s son, Donald Jr.