White House legislative director Marc Short also told NBC's Chuck Todd on "Meet the Press" that Kelly had not offered his resignation. “He will step aside anytime the president doesn’t want him to be there," Short said. "But John Kelly has not offered his resignation. John Kelly is doing an outstanding job," he added.

“There’s a lot of good things that have been happening since the chief is there,” Mulvaney told Chris Wallace on "Fox News Sunday."

Mulvaney went on to say that those saying the chief of staff could soon leave the White House are people “unhappy that they've lost access to the president" since Kelly assumed his role in the West Wing last year.

"I am extraordinarily pleased with the job the chief has been doing," he added. "I think the president is as well."

Mulvaney said Porter was not entirely forthcoming with the president about the allegations made by his ex-wives and that the problem does not lie with Kelly.

"You’re going to want to believe and trust the people that are close to you and that you know. You see, I think the problem here was with Mr. Porter, not with the chief of staff," Mulvaney said.

The president drew backlash on Saturday after he tweeted that "lives are being shattered ... by a mere allegation."

Peoples lives are being shattered and destroyed by a mere allegation. Some are true and some are false. Some are old and some are new. There is no recovery for someone falsely accused - life and career are gone. Is there no such thing any longer as Due Process? — Donald J. Trump (@realDonaldTrump) February 10, 2018

The president's tweet came after a second staffer, former White House speechwriter David Sorenson, abruptly resigned. He has denied allegations of domestic abuse, saying he was the victim.

Conway on Sunday defended the tweet, saying Trump was referring to how the allegations are being handled.

"What the president is saying when he is talking about due process, he’s right in this way, we are a country of laws," Conway said on CNN's "State of the Union."

"But we as individuals have a duty to assess everybody on a case-by-case basis," she added.

Conway said she has no reason not to believe the allegations raised against Porter.

"In this case, you have contemporaneous police reports, you have women speaking to the FBI under threat of perjury ... you have photographs, and when you look at all of that pulled together, Rob Porter did the right thing by resigning," she said on CNN. "I have no reason not to believe the women."

The White House, however, has come under fire for how the situation was handled.

Deputy press secretary Raj Shah reportedly drew Trump's ire when he told reporters last Thursday that the White House could have handled the situation better.

Short on Sunday stressed that the White House is taking the allegations seriously.

"I think that Rob is a friend to many of us in the administration. Rob is somebody who is a Rhodes Scholar, is a Harvard-educated guy. He did a great job as staff secretary," Short told NBC.

"But there can be no tolerance for domestic abuse. And there can be no tolerance for violence against women, and we have to be absolutely clear about that. I think there was probably some — in the process some lack of communication between different elements in the White House," he said.

Mulvaney echoed Short's sentiment on the White House's stance on domestic abuse.

“We don’t tolerate it at all,” he said. “You cannot put trust in people who would do that to their spouse of either gender, so we have a zero-tolerance policy for it."

Short and Conway defended the White House's decision to clear Porter for a security clearance, saying the administration took the same steps as previous administrations.

"This is the same process in the administration that the Obama administration used, the Bush administration used and others, and that the FBI runs this clearance process," Short said. "And when they provide somebody an interim security clearance, that means that they’ve done an initial vet and say, this person is okay, there are some mitigating circumstances we’re going to continue to investigate."

"There’s a lot of information going out in the public right now being reported as fact by people who couldn’t possibly know," Conway said referring to the process of obtaining a security clearance.

"And, and so they won’t discuss individual FBI investigations. We have to all respect that, I believe. But at the same time, an interim security clearance was granted to Rob Porter to allow him to continue. That is the case for others who work in the White House currently and in other White Houses," she continued. "But this is a process that’s gone on a long time, and we respect and rely upon that process."