Secretary of State Rex Tillerson is "taking a little time off" for vacation following an extended trip to Europe and the Middle East, his spokeswoman said.

"He does have the ability to go away for a few days on his own," State Department spokeswoman Heather Nauert told reporters. "He's got a lot of work, he just came back from that mega-trip overseas ... so he's entitled to take a few days for himself."

Tillerson joined President Trump for a trip to Poland and a meeting with Russia leaders at the G-20 summit in Germany. He proceeded then to Ukraine, which is being destabilized by Russian military forces and separatists, before a swing through the Middle East to address a malingering diplomatic crisis between U.S. partners in the region.

But the vacation also follows rumors that frustration with President Trump might motivate him to leave the administration.

Nauert dismissed those suggestions.

"The secretary has been very clear he intends to stay here at the State Department," she said. "We have a lot of work that is left to be done ahead of us. He recognizes that, he is deeply engaged in that work, we have meetings scheduled, he has meeting scheduled for the rest of the week here in Washington. He does, however, serve at the pleasure of the president, just as any cabinet official."

Tillerson acknowledged that the trip through Europe and the Middle East had been a grind, leaving him "tired." He hinted at the time at chafing at the limitations of his new job.

"Well, it is a lot different than being CEO of Exxon because I was the ultimate decision maker," Tillerson told reporters, per the New York Times. "That always makes life easier."

Trump's White House team has clashed with Tillerson over staffing issues, vetoing various people whom the former CEO has chosen as his preferred State Department lieutenants. At one point, Tillerson criticized a White House aide, only to receive a rebuke from Jared Kushner, Trump's son-in-law.

"Colleagues are capable of frank exchanges," R.C. Hammond, a State Department spokesman, said in June when the report surfaced. "Evaluating nominees did get off to a slow start, but it is now moving along at a pretty good clip."

Tillerson's tension with the White House over staffing decisions has continued, but he's not going anywhere, Hammond added Monday.

"As long as there are rogue regimes pursuing nuclear weapons or terrorists seeking safe haven, the secretary will remain on the job," he told Buzzfeed.