However, Russia, Tillerson said, has shown it seeks to define a new post-Soviet global balance of power, one in which Russia, by virtue of its nuclear arsenal, seeks to impose its will on others.
The hope from the White House, the source said, is to push out the plan to replace Tillerson and then "wait for him to punch out". On several occasions, the president publicly undercut his diplomatic initiatives.
Trump surprised many observers when he tweeted that Tillerson was "wasting his time" pursuing contacts with North Korea, and Tillerson was quoted as having said - though he denied it - that the president was a "moron".
But in response, Mr Trump said: "I guess we'll have to compare IQ tests".
Ahead of his week-long visit to Europe, Tillerson described Russian Federation as one of the "major challenges" facing Europe and the US. "I serve at the appointment of the president and I am here as long as the president feels I can be useful to achieving his objectives".
The ouster of Mr. Tillerson would end a turbulent reign at the State Department for the former Exxon Mobil chief executive, who has been largely marginalized over the previous year. "Yes, sometimes, he changes his mind".
Tillerson answered that "the president speaks for himself".
Corker "said the president quote has castrated you before the world stage", CNN's Jake Tapper said to Tillerson. She says Tillerson continues to lead the department. Bob Corker (R-TN), that Trump has been damaging Tillerson's efforts and undercutting him at seemingly every opportunity.
A senior administration official who spoke recently with Tillerson says the former Exxon Mobil CEO felt secure in his position and was focused on his State Department reorganization and other diplomacy matters. "I don't know who that is".
If carried out, the staff changes would be the latest in a string of firings or resignations in the Trump administration including the departures of the chief of staff, national security adviser and Federal Bureau of Investigation director. The favored candidate to replace Tillerson is current CIA Director Mike Pompeo, which would leave a vacancy at the CIA.
Sen. Cotton, meanwhile, is a staunch conservative and ally to the president, best known for hawkishness on both foreign policy and immigration issues.