The U.S. Senate on Wednesday, by an overwhelming majority, approved an amendment to increase vigilance along the border with Mexico, a decisive step toward a final vote on immigration reform.

The vote was 69-29 in favor of the amendment proposed by Republicans John Hoeven of North Dakota and Bob Corker of Tennessee, which imposes a number of conditions before undocumented immigrants can be awarded permanent residence.

With this vote, the amendment will be incorporated into the bill for comprehensive immigration reform, which will be voted on before the weekend.

Before the vote on the amendment, Senate Majority Leader Harry Reid, a Democrat from Nevada, praised the work of the bipartisan "Gang of Eight" who negotiated and crafted the immigration reform bill and formally presented it in April.

But several Republican senators, among them John Cornyn and Ted Cruz of Texas and Iowa's Charles Grassley, voted against the border security amendment.

The Hoeven-Corker amendment establishes five conditions that must be met before undocumented immigrants may get permanent residence, which - even so - can only happen after they wait at least 10 years.

Undocumented immigrants who fulfill a series of requirements will first receive temporary permission to live legally in the United States.

Among its other elements, the amendment doubles to 40,000 the number of Border Patrol agents to be hired by 2019, orders the construction of a wall 1,126 kilometers (about 700 miles) long and - in a $3 billion package - increases monitoring along the border by using drones and other high-tech equipment.

To turn off the faucet on future flows of undocumented immigrants, it also establishes the obligatory use of the E-verify program, so that companies may ascertain the immigration status of their new employees and avoid hiring those who are in the country illegally. EFE