Sen. Marco RubioMarco RubioOvernight Defense: Commander calls North Korea crisis 'worst' he's seen | Trump signs VA order | Dems push Trump to fill national security posts What’s with Trump’s spelling mistakes? Boeing must be stopped from doing business with Iran MORE (R-Fla.) on Thursday praised a breakthrough deal on border security measures, saying he hoped it would solidify bipartisan support for the Gang of Eight immigration reform bill.

“I’ve been saying that for weeks, that the entire effort for immigration reform hinges on whether or not we get the border security parts of the bill right,” he said in an interview on Fox News.

“If you look at what’s being proposed here, this is a dramatic expansion and improvement in border security that I hope will allow finally for this legislation to have the support it needs.”

Rubio’s praise could be critical in helping the measure win Republican support for passing immigration reform with an overwhelming majority in the Senate.

Rubio helped draft the bipartisan immigration bill as a member of the Gang of Eight, but has been in the crosshairs of conservatives who have criticized the legislation as weak on border security.

At a Tea Party rally on Capitol Hill on Wednesday, the crowd booed at the mention of Rubio’s name, and the rising GOP star has struggled to maintain the backing of some colleagues who formerly supported his efforts.

The Florida senator has pushed for additional measures on border enforcement and suggested earlier this month he might decline to support the bill he drafted.

Rubio said the terms of the new amendment, crafted by Sens. Bob CorkerBob CorkerState spokesman: Why nominate people for jobs that may be eliminated? The Hill's 12:30 Report Senate Foreign Relations chair: Erdogan referendum win 'not something to applaud' MORE (R-Tenn.) and John HoevenJohn HoevenCongress nears deal on help for miners Overnight Energy: Lawmakers work toward deal on miners’ benefits Congress nears deal on help for miners MORE (R-N.D.), should allay the concerns of those who say border security is lacking in the Gang of Eight bill.

“It’s a dramatic improvement in border security. It’s a major surge in border enforcement,” Rubio said. “We’re a sovereign country — we have a right to protect our border … and that’s why this is so critical.

“As long as we have this crisis on the southern border, it’s going to require a surge of resources like the one that this amendment outlines,” he added.

Rubio added that he understood conservatives were wary about passing immigration reform without assurances that more would be done to stop illegal border crossings.

“Clearly there are people who are unhappy with this issue, and I understand that, I really do,” he said. “People are frustrated that America is so generous when it comes to immigration, and yet people have taken advantage of our laws … I share those frustrations.

“But leaving in place what we have right now is not an option,” he added. “We have to fix this. I think this amendment is a dramatic improvement on border security unlike anything that’s ever been proposed or had a chance of passing in the past.”

Supporters of immigration reform are hopeful that the border security deal will help the bill pass with strong support, giving it momentum in the GOP-controlled House, where it faces an uphill climb.

Speaker John BoehnerJohn BoehnerLobbyists bounce back under Trump Business groups silent on Trump's Ex-Im nominee Chaffetz won't run for reelection MORE (R-Ohio), though, has said he will not push measures that lack the support of a majority of the GOP conference and has said the House will take up its own immigration proposals.