Susan Walsh/AP Photo

Today's expected Senate briefing on the gang of eight immigration bill was postponed.

Sen. Marco Rubio, R-Fla., was scheduled to explain their nearly finished proposal, but senators coming out of the closed door meeting on Capitol Hill told reporters the gun issue took up the entire agenda.

Sen. Jeff Sessions, R-Ala., a powerful critic of immigration reform, said the gang of eight was not ready.

Sessions said, "I guess he wasn't ready. They didn't seem to be interested in doing that," he told reporters. "I didn't get the impression there was any interest to get that done today [among the gang of eight]. The impression I got was that they hoped to be able to do it next week."

Sen. Jeff Flake, a Republican of Arizona and one of the gang of eight, told reporters the bill could be ready by Friday or slip into next week.