WASHINGTON — President Donald Trump has grown frustrated with Homeland Security Secretary Kristi Noem and has begun to consider possible replacements, lawmakers and people familiar with the discussions tell NBC News.

Trump has been speaking this week with Republican lawmakers about his displeasure with Noem and has made clear in those conversations that he is considering replacing her, according to two Republican lawmakers, a person familiar with White House’s thinking and three people familiar with the president’s private discussions.

White House officials have already discussed names of potential replacements for Noem, including Republican Sens. Markwayne Mullin of Oklahoma and Steve Daines of Montana, according to two of the people familiar with the discussions.

No decision has been made by the president, the sources say, but that he has told lawmakers that he is unhappy with Noem’s testimony this week before House and Senate committees.

Trump was particularly frustrated by Noem’s response when she was repeatedly asked about her role in approving contracts, specifically a $220 million ad campaign to encourage immigrants to self-deport, the sources said.

At one point during questioning, Noem told Sen. John Kennedy, R-La., that Trump knew about her decision to approve the ad campaign contracts — an answer that did not sit well with the president, the sources said. The ad contracts went out through a process that limited competitive bidding.

Kennedy told reporters he had spoken with the president about the exchange.

“The president of the United States called me, and I’m not going to speak for him, folks, but, I would put it this way: his recollection and her recollection are different.”

“I can assure you, he is not happy with her,” said one of the lawmakers who spoke with Trump this week, who, like others, were granted anonymity to discuss sensitive internal discussions. “She did horrible in the hearings and has made a lot of errors.”

Asked for comment on Trump’s frustrations with Noem, a Department of Homeland Security spokesperson said, “Secretary Noem serves as the pleasure of the President. She is honored to serve the American people and lead DHS. Under her leadership, we have the most secure border in American history, 3 million illegal aliens left the United States, and we now have the lowest murder rate in 125 years.”

The White House did not respond to a request for comment about the president’s thinking on Noem.

Asked whether Noem would be replaced, Sen. Lindsey Graham, R-S.C., responded: “Time will tell.”

When asked whether he still had confidence in her, he gave the same response.

The sources say that while Trump has at times been unhappy with Noem’s performance in leading DHS — most recently over her handling of shootings by immigration enforcement officers in Minneapolis — his frustrations have really escalated this week.

If he were to replace Noem, it would mark the first Cabinet secretary to exit in Trump’s second term. Noem also has been at the forefront of deportation efforts, one of the president’s top policy priorities.

One GOP senator told NBC News that Trump had been calling around Capitol Hill asking for input on Noem since last year, and that her performance during the hearings this week were “water boiling over the edge of the pot.”

The White House has contacted Daines’ office, the two sources said. Daines recently announced he will not seek re-election to spend more time with his family.

Former Utah congressman Jason Chaffetz has expressed interest in replacing Noem, according to two of the people familiar with the discussions. The Fox News contributor signaled his interest directly to Trump, and has over the past few weeks discussed with the president joining the administration in some capacity, the sources said.

Still, sources stressed that Noem’s ouster is not definite and no successor has been chosen at this time.

Another possible complication is that DHS funding expired Feb. 13, forcing a partial shutdown of the department that affects the Transportation Security Administration, the Federal Emergency Management Agency, the Coast Guard and cybersecurity.

Democrats have been negotiating with the White House over changes to immigration enforcement to secure their votes to reopen the agency in full.

Sen. Richard Blumenthal, D-Conn., said that Noem’s ouster might could help negotiations.

“Kristi Noem’s resistance to common sense reforms in ICE, her implacable opposition to lawfulness, ought to get her fired. And then it might be easier for us to negotiate, because at least some responsiveness, to the need to stop this lawbreaking,” he said.