The No. 2 Republican on the Senate Foreign Relations Committee sent an early signal Wednesday that he would not defer to anyone else hoping to replace departing Chairman Bob Corker, who announced his retirement Tuesday afternoon.

Sen. James E. Risch (Idaho), the most senior Republican member of the committee after Corker, would not directly address the question of whether he would seek the chairman's gavel when Corker (Tenn.) departs the Senate at the end of 2018. But he stressed that seniority will be the deciding factor — meaning that if he wants it, he will get it.

"We have a long, clear history of how these things are resolved in the Senate," Risch said. "We will follow that route when we get there."

Risch has been in the Senate only two years longer than Sen. Marco Rubio (R-Fla.), but his more senior position all but quashes any aspirations that Rubio may have had of taking the chairman's gavel. Rubio told reporters on Wednesday that "if Jim Risch wants to be chairman, I'll support him."

Risch and Rubio are quite close. Risch was one of Rubio's earliest supporters in his campaign for the Republican presidential nomination in 2016. The two sit on several committees together, including the Intelligence Committee and the Small Business Committee in addition to the Foreign Relations Committee. Risch outranks Rubio by one notch of seniority on each, meaning that if Risch takes over the Foreign Relations Committee, Rubio is probably next in line to inherit the gavel on the Small Business Committee, which Risch chairs.

Still, in his time on the Foreign Relations Committee, Rubio had made a concerted effort to establish himself as an active and visible diplomatic voice on foreign relations, particularly in matters concerning Russia, Cuba and Venezuela.

Rubio also has a track record of challenging President Trump on some matters of foreign policy — particularly when it comes to human rights — in a way that Risch does not. Human rights matters, as well as working closely with Democrats, have been hallmark priorities of Corker's term as committee chairman.

Corker said in an interview Tuesday that he was not going to personally involve himself in discussions about who would succeed him as chairman. But he did place a phone call to Risch, he said, joking that his retirement must have made Risch the "happiest person in the United States," other than Corker's family.