In order to increase Republican support for a bipartisan immigration bill, the GOP will introduce a border-security proposal that would allot tens of billions of dollars to secure the southwest border, in addition to granting citizenship to millions of people in the country illegally.

The amendment would require 20,000 more border agents, completing a 700-mile fence on the frontier with Mexico and taking other steps before undocumented immigrants can get green cards, GOP sponsors of the compromise said Thursday according to CNN.

The proposal, negotiated by a group of Republican and Democratic senators from both parties known as the "Gang of Eight," also calls for deploying $3.2 billion in technology upgrades sought by the border patrol. It also seeks worker verification and border entry-exit controls before the 11 million immigrants living illegally in America can get permanent residency.

On Thursday, GOP Sen. John Hoeven of North Dakota noted that the bill would allow undocumented immigrants to get temporary legal status as "registered provisional immigrants," but said the increased security measures must be in place before immigrants can get green cards to make them permanent residents.

One of the writers of the bill, Sen. Marco Rubio (R-Fla.) called the amendment a "dramatic improvement on border security" and emphasized getting the nation's undocumented immigrants on a clear path to citizenship right away without certification that the border is secure, reports USA Today.

Rubio said it would be up to Congress to decide whether the border is secure enough for unauthorized immigrants to actually obtain permanent legal status. However, GOP Rep. Grassley and others say the bill is too vague on that point, and has too many loopholes.