The White House press secretary, Sarah Huckabee Sanders, has become "tired" of being the face of some of the controversial policies emerging from the Trump administration, one of her friends told Vanity Fair.

Sanders faced considerable blowback this week trying to defend the "zero tolerance" immigration policy that prioritizes criminally prosecuting adults caught crossing the US-Mexico border illegally.

"She's tired of taking on water for something she doesn't believe in," Sanders' friend told Vanity Fair.

The White House press secretary, Sarah Huckabee Sanders, has become "tired" of being the face of some of the controversial policies emerging from the Trump administration, one of her friends told Vanity Fair on Wednesday.

"She's tired of taking on water for something she doesn't believe in," the friend said.

"She continues to have a frustration that the policies are all over the map," another person familiar with the situation told Vanity Fair. "It's not a good look for Sarah."

Similar to her predecessor Sean Spicer, Sanders has developed a tenuous relationship with members of the White House press corps during her tenure. As one of the Trump administration's principal representatives, Sanders is frequently tasked with defending many of President Donald Trump's more controversial statements and policies. As a result, Sanders has also become increasingly combative with reporters who cover the administration.

This week, amid uproar over the Trump administration's new "zero tolerance" immigration policy, Sanders defended its prioritization of criminally prosecuting adults caught crossing the US-Mexico border illegally, leading them to be separated from any children they're traveling with. The policy has been condemned by lawmakers from both parties, and it has galvanized civil-rights groups.

The ongoing backlash apparently kept Sanders largely out of public view for the second day in a row; there was no on-camera press briefing at the White House on Tuesday or Wednesday.

On Monday, Homeland Security Secretary Kirstjen Nielsen faced pointed questions over the zero-tolerance policy.

Earlier in June, White House sources told CBS News that Sanders had told friends she planned to leave the administration at the end of the year. Sanders later criticized the report but stopped short of denying it.