President Trump denied rumors Secretary of State Rex Tillerson could be leaving his post, despite numerous reports to the contrary.

“The media has been speculating that I fired Rex Tillerson or that he would be leaving soon – FAKE NEWS!” he tweeted Friday. “He’s not leaving and while we disagree on certain subjects, (I call the final shots) we work well together and America is highly respected again!”

Sources had told Fox News that Tillerson was expected to step down from his post in January. Discussions of Tillerson’s exit came amid reports of growing tension between him and Trump.

Here’s a look at who Tillerson is and what he did before joining the ever-evolving Trump administration.

Who is Rex Tillerson?

Tillerson, 65, grew up in Texas and Oklahoma. He graduated from the University of Texas at Austin, where he earned a bachelor of science degree in civil engineering.

Tillerson is also known for his involvement with the Boy Scouts of America. He served as the organization’s national president from 2010 to 2012.

Following the oft-criticized speech Trump gave to the Boy Scouts in July, Tillerson reportedly threatened to resign from the State Department.  

What about his resume?

Prior to becoming secretary of state, Tillerson did not have any experience in the public sector.

Before joining the administration, Tillerson was the chairman and CEO of Exxon Mobile. He served in that role beginning in 2006, but he actually joined the company in 1975 as a production engineer, according to an archived version of his Exxon biography.  

What has he done as secretary of state?

New U.S. Secretary of State Rex Tillerson (L) is sworn in by U.S. Vice President Mike Pence (R) as his wife Renda St. Clair holds a Bible, accompanied by U.S. President Donald Trump during a ceremony at the Oval Office of the White House in Washington, U.S., February 1, 2017. REUTERS/Carlos Barria      TPX IMAGES OF THE DAY - RC168B84F770

 (Reuters/Carlos Barria)

Tillerson’s tenure as secretary of state has been contentious with Trump. He reportedly called Trump a “moron” in front of other Cabinet officials in July. Following reports of the remark, Tillerson gave an unusual personal address and said he was not planning to quit.

As secretary of state, Tillerson has traveled extensively – visiting Australia, Europe and Mexico, among other places. He assumed the position of secretary of state on Feb. 1.

Tillerson’s ties to Russia have also been scrutinized – a criticism that has plagued many Trump administration officials as investigators continue to look into Russian meddling in the 2016 election.

Tillerson was named vice president of Exxon Ventures (CIS) Inc., and president of Exxon Neftegas Limited in 1998. In those roles, Tillerson was tasked with overseeing Exxon’s holdings in Russia and the Caspian Sea, his Exxon biography stated. He met with Russian President Vladimir Putin multiple times before becoming secretary of state.