(CNN) Tennessee Republican Sen. Bob Corker said Tuesday he will retire at the end of 2018.
"After much thought, consideration and family discussion over the past year, Elizabeth and I have decided that I will leave the United States Senate when my term expires at the end of 2018," Corker said in a released statement.
Corker is the Senate's foreign relations committee chairman and had told CNN earlier this month that he was considering whether to run again.
"When I ran for the Senate in 2006, I told people that I couldn't imagine serving for more than two terms," Corker said in his statement Tuesday. "Understandably, as we have gained influence, that decision has become more difficult. But I have always been drawn to the citizen legislator model, and while I realize it is not for everyone, I believe with the kind of service I provide, it is the right one for me."
Corker, who was at one time among those considered a candidate to be President Donald Trump's secretary of state, had been increasingly critical of the President in recent months.
"The President has not yet been able to demonstrate the stability nor some of the competence that he needs to demonstrate in order to be successful," Corker said last month, according to a video posted by local news website Nooga.com, in reference to Trump's handling of violence related to a white supremacist rally in Charlottesville, Virginia. Trump and his press secretary responded with their own criticism. Corker later said he had a "strong" relationship with the President, and the two had a meeting at the White House on September 15.
But sources familiar with private conversations between Trump and Corker told CNN the two made up since their August fight, and that the President wanted Corker to run for reelection.
RELATED: Donald Trump met with Bob Corker on Friday. Here's a look back at their relationship
Corker, 65, had been struggling and weighing the decision for months. The Tennessee Republican has gained prominence in the Senate as an outspoken leader on not just foreign relations, but also on domestic issues. He's also well-connected to GOP leadership and is only in his second term.
In his statement Tuesday, Corker said that he believed "the most important public service" he had to offer would come in upcoming months.
"I want to be able to do that as thoughtfully and independently as I did the first 10 years and nine months of my Senate career," Corker said.
"Serving the people of Tennessee in this capacity has been the greatest privilege of my life. And as I spent the month of August traveling across our great state, I was reminded that we live in a unique place full of people who care deeply about the direction of our country."