"The public is so far ahead of the Congress on this subject," she said. "I believe that whatever passes the Congress now will not be the end of the day for this issue."
The Senate is expected to move to gun control when it returns to Washington next month, but the bill on the floor will not include a new assault weapons ban on certain semi-automatic guns with military features.
Senate Majority Leader Harry Reid (D-Nev.) said last week he doesn't have the votes to pass such a measure.
The bill will also include expanded background checks, although it is not clear a measure with those rules can clear the Senate.
Gun control supporters, including Pelosi, argue that the public wants Congress to do more on the issue, particularly in the wake of the December shooting in Newtown, Conn. that left 20 elementary school children dead.
Pelosi said the failure of Congress to pass tough gun control measures would simply set up a new fight.
"Say it doesn't prevail, just for the sake of argument," she said. "It argues all the more strongly for having the toughest; best; most effective background checks, instead of diluting the background checks, because we might not succeed with the assault weapons ban."