Colorado Senator Ken Salazar plans to meet with President Bush and other senators this week to discuss immigration.

But the Democrat says he's deeply concerned about the president's plan to send up to six-thousand National Guard troops to increase enforcement at the U.S.-Mexico border.

Bush's proposal comes as senators began debate on an immigration bill that would increase security at the border and create a guest worker program for foreigners.

Bush supports such a program.

Republican Senator Wayne Allard says he opposes the guest worker plan, but believes sending troops to the border is appropriate.

His support was tempered, though, by concern that the mission could make it more difficult for the National Guard to respond to emergencies.

Meanwhile, Republican Congressman Tom Tancredo says the plan to send troops was good news, but is blasting the president's support of the guest worker program.