White House press secretary Sarah Sanders said Monday that President Trump still has confidence in Secretary of State Rex Tillerson, after appearing to criticize the nation's top diplomat in weekend tweets.

"He does, yes," Sanders said at the daily White House press briefing.

Sanders said she believed Trump had spoken with Tillerson, a former Exxon Mobile CEO, since his Sunday social media posts, but that "I'll have to verify."

Trump's tweets included: "I told Rex Tillerson, our wonderful Secretary of State, that he is wasting his time trying to negotiate with Little Rocket Man."

In another tweet, the president said: "Save your energy Rex, we'll do what has to be done!"

Hours later, State Department spokeswoman Heather Nauert tweeted in response: "Diplomatic channels are open for #KimJongUn for now. They won't be open forever @StateDept @potus."

Sanders said during the Monday briefing, however, that the U.S. would only be willing to speak about the return of three Americans currently detained by North Korea.

"We've been clear that now is not the time to talk," she said. "The only conversations that have taken place or that would would be on bringing back Americans who have been detained, like with Otto. Those were the type of conversations that this administration would be willing to have. Beyond that, there will be no conversations with North Korea at this time."