Langer's position has been under the spotlight after multiple media reports that players have wearied of his intense coaching style.
Khawaja, who famously clashed with Langer on the Amazon Prime docu-series "The Test", said the Western Australian deserved more time in charge.
"He deserves the opportunity to coach Australia in the T20 World Cup, he deserves the opportunity to coach Australia in the Ashes," Queensland captain Khawaja said on his YouTube channel.
"If after all that, things are still not going well ... that is when you look at things and think 'OK, maybe do we need to change something?'"
Khawaja said he was disappointed players appeared to be airing grievances through the media rather than keeping issues in-house.
"How do you think JL (Langer) feels? He probably feels like the guys in the team are stabbing him in the back. And that's what it looks like," Khawaja said.
"It's a really bad look and it's something the group needs to sort out ASAP."
Australia captain Tim Paine said he and other senior players had "robust" discussions with Langer to clear the air last week.
Khawaja had a heated exchange with Langer during the 2018 tour of United Arab Emirates as captured in "The Test".
Media pundits have cast Khawaja as a victim of standing up to Langer, linking the UAE episode with the batsman's omission from the Australia team for the past two years.
Khawaja, who has a batting average above 40 from his 44 tests, said his relationship with Langer had nothing to with his non-selection.
"My relationship with Justin Langer is really good. To be honest, I still talk to him, still text him here and there, and that's because we have a lot of respect for each other," he said.