President Trump on Monday expressed openness toward an investigation of Louis DeJoy, his postmaster general, who is facing scrutiny after former employees of his previous private company said they felt pressured to make donations to Republican candidates for which they were later reimbursed.

In a Labor Day news conference at the White House, when asked whether he was open to a campaign finance investigation of DeJoy, Trump said, “Sure, sure, let the investigations go.” He also said DeJoy should lose his job “if something can be proven that he did something wrong.”

The president was responding to questions about a recent Washington Post story, which found that over a decade while DeJoy was chief executive of New Breed Logistics, employees said they were urged by DeJoy and his top aides to contribute to GOP candidates and then were reimbursed through bonuses — a practice that would be unlawful.

Trump, however, also offered tepid support for DeJoy, saying he did not know much about The Post’s report and twice calling DeJoy “a very respected man.”

In response to detailed questions from The Post, Monty Hagler, a spokesman for DeJoy, said the former New Breed chief executive was not aware that any employees had felt pressured to make donations.

After repeatedly being asked, Hagler did not directly address the assertions that DeJoy reimbursed workers for making contributions, pointing to a statement in which he said DeJoy “believes that he has always followed campaign fundraising laws and regulations.”

Late Monday, Rep. Carolyn B. Maloney (D-N.Y.), chairwoman of the House Oversight and Reform Committee, said the panel would launch an investigation of DeJoy and called for his immediate suspension.

Since being appointed the head of the U.S. Postal Service, DeJoy has come under additional scrutiny for his severe cost-cutting measures that critics say are wreaking chaos and causing delays, prompting accusations of political bias — especially after Trump threatened to block USPS funding to limit its ability to process ballots for the November election.

In his wide-ranging 45-minute news conference, Trump also weighed in on the progress of a coronavirus vaccine, as well as his relationship with the nation’s military — for which he has come under renewed criticism after an Atlantic article detailed his alleged denigration of the troops and military service generally. According to the Atlantic’s reporting, the president dismissed Americans who died in war as “losers” and “suckers.”

Trump said his administration will end the coronavirus pandemic through Operation Warp Speed, which seeks to produce a vaccine in record time, though his stated timeline clashes with that described by experts in his administration. The president said that a vaccine could even come “during the month of October” — just weeks before Election Day, which could be a tremendous boost to his reelection hopes.

“The vaccine will be very safe and very effective, and it’ll be delivered very soon,” Trump said. “You could have a very big surprise coming up.”

However, many experts in Trump’s administration have cautioned that such a rapid timeline seems overly optimistic. The lead scientific adviser for Operation Warp Speed, for instance, told NPR that a vaccine was “possible but very unlikely” to be available by October or November.

Former Food and Drug Administration commissioner Scott Gottlieb told “Face the Nation” on Sunday that a vaccine for widespread use will likely be “a 2021 event.” If a vaccine were created before the end of 2020, it would probably be used for targeted populations, such as health-care workers and nursing home residents, Gottlieb said. The country could see the end of the more acute phase of the virus outbreak because more people will probably be infected between now and then, he said.

When pressed, Trump also used the news conference to push back on the Atlantic story, calling it “a hoax.”

The president had previously used harsh language against the late senator John McCain (R-Ariz.) — a prisoner of war in Vietnam and a military hero whose family has a long tradition of serving in uniform — saying in 2015 that McCain was a “loser” and that he, Trump, preferred “people who weren’t captured.” But Trump said his animosity toward McCain was long-standing and philosophical and should not be viewed as evidence that he as commander in chief does not respect the troops.

“I’ve always been on the opposite side of John McCain,” Trump said, explaining that while he personally has been skeptical of overseas entanglement, “John McCain liked wars.”

Trump continued: “I will be a better warrior than anybody, but when we fight wars, we’re going to win them. And frankly, I was never a fan of John McCain.”

Referring to the Democratic nominee, former vice president Joe Biden, Trump said, “Biden shipped away our jobs, threw open our borders and sent our youth to fight in these crazy endless wars.”

And he used the opportunity to try to distinguish his relationship with the top military brass (not so great) from his bond with troops on the ground (better, he claimed).

“I’m not saying the military’s in love with me — the soldiers are,” Trump said. “The top people in the Pentagon probably aren’t because they want to do nothing but fight wars so that all of those wonderful companies that make the bombs and make the planes and make everything else stay happy.”

Lateshia Beachum and Amy Gardner contributed to this report.