Former Republican presidential candidate Marco Rubio is expected to announce he is running for re-election to the Senate, yielding to intense pressure from party leaders determined to keep his Florida seat in GOP hands.

Rubio was to reveal his plans later in the day Wednesday, according to a GOP official who spoke on condition of anonymity ahead of the official announcement.

Senate Majority Leader Mitch McConnell told reporters Wednesday that a Rubio re-election bid would be "a great outcome" that would likely mean Republicans would hang onto the seat.

McConnell had led the effort to pressure Rubio to abandon his retirement plans and run for re-election instead. Rubio had repeatedly said he planned to be a private citizen come January, and he was widely expected to enter the private sector before making another presidential bid in 2020.

But with Republicans at risk of losing their slim Senate majority in November's elections, GOP leaders were concerned that the Republican candidates who emerged for Rubio's seat were not up to the task of winning in a large, expensive state like Florida amid the intraparty uproar created by Donald Trump's candidacy.

The announcement comes just days ahead of Friday's filing deadline for his seat.