(CNN) -- Days before the Republican National Convention kicks off in Tampa next week, former presidential candidate Newt Gingrich released his delegates in a symbolic gesture and urged them to vote for Mitt Romney.
"I hereby release all delegates bound or pledged to me under any and all state laws or party rules," Gingrich wrote in a letter to delegates, which was posted on his website Tuesday night. "At the same time, I call upon them and all Americans committed to a safer and more prosperous American future to join Callista and me in strongly supporting the Romney-Ryan ticket."
During his own White House bid earlier this year, Gingrich repeatedly vowed to continue his campaign all the way to the convention. Faced with mounting debt and Romney's all-but-certain lock-up of the Republican nomination, Gingrich ended his campaign in early May.
He has since endorsed Romney, though he's been known to offer less-than-enthusiastic praise for the former Massachusetts governor. Instead, Gingrich largely focuses on a need to defeat President Barack Obama, a message he reiterated in his letter Tuesday.
"With the Republican National Convention beginning in Tampa within the next few days, it is time now for all Republicans to come together in common purpose to defeat President Barack Obama and Vice President Joe Biden," Gingrich wrote. "Everyone must do their part and Callista and I are committed to doing everything that we can."
Romney passed the 1,144 delegate threshold needed to clinch the nomination on May 30. According to CNN estimates, Gingrich had collected 142 delegates by the time he ended his presidential bid.
While the former House speaker won't be delivering an address at the GOP convention next week, he's slated to host "a series of public policy workshops for delegates." Earlier this month, Gingrich said on CNN's "The Situation Room" that his role at the convention will make him more than visible in Tampa.
"Trust me, anybody who wants to see me will have more than enough opportunity during the convention. I'll probably have more total time than anybody thought possible," Gingrich said.