President Obama will hold an event Wednesday with law enforcement officials and mothers of gun violence victims, marking the 100th day since the Newtown, Conn., mass shooting.
The president is looking to build momentum for a package of new gun control measures to be considered by the Senate early next month.
On Tuesday, White House spokesman Josh Earnest refused to speculate on whether the president believed Congress would pass any new gun controls.
"I don't want to stand here and predict the future," Earnest said.
But Earnest said that a promised vote on an amendment to add the assault weapons ban to the Senate's gun bill itself amounted to progress.
"Because of all the talk of the president and because of his advocacy on this issue, there will be a vote in the United States Senate ... I can't stand here and guarantee it is going to pass, but it is a question that 100 United State senators will have to ask themselves when they wake up in the morning," Earnest said.
Earnest also disputed the notion that Obama was pressing now over fear that momentum on a gun bill had stalled as time passed since the Newtown shooting. He noted that by the White House's count, the president and vice president had held 20 events on gun violence since the shooting, and he said the decision to appoint Vice President Biden as the point man on the issue underscored the importance of the issue.
"This is something that the president has been engaged on from the beginning," Earnest said.