US Secretary of State Rex Tillerson has admitted he "didn't want" the job and had planned on retiring this year before his wife convinced him otherwise.

The former Exxon Mobil CEO - who has no previous government experience - was one of Donald Trump's most notable and surprising major appointments.

In an interview with the conservative news site Independent Journal Review, Mr Tillerson said he had not met Mr Trump before the election.

They first met the then president-elect for a conversation 'about the world'.

"When he asked me at the end of that conversation to be secretary of state, I was stunned," the 65-year-old Mr Tillerson told reporter Erin McPike during his recent visit to Asia.

"I didn’t want this job. I didn’t seek this job [...] My wife told me I’m supposed to do this."

He said that he had planned on retiring this month - "I was going to go to the ranch to be with my grandkids" - before he received the unexpected job offer.

Explaining that he serves "at the pleasure of the president", Mr Tillerson suggested he has not regretted his decision to take on his country's top diplomatic role.

"My wife convinced me," he said. "She was right. I’m supposed to do this."

President Trump's first budget proposals include a significant 28% cut to the state department's budget, and Mr Tillerson noted "we haven’t gotten that far yet" when asked about how the proposed cuts would impact his department.

Today, Mr Tillerson is hosting a meeting in Washington of foreign ministers from countries involved in the fight against Islamic State.

Those in attendance will "review the campaign to date and strategise how to further accelerate the defeat of ISIS".