The Democratic majority House passed the legislation on Feb. 27. It won only eight Republican votes and McConnell, R-Ky., had no plans to bring up the bill.

Schumer touted the measure as bipartisan and said McConnell needs to bring it to the floor immediately by calling an emergency session. The Senate is currently adjourned for the August recess.

Schumer was joined at the press conference by Rep. Pete King, R-N.Y., who co-sponsored the bill.

King also urged Trump to get involved in facilitating a Senate vote on the measure.

“If the president would come out and say, ‘Background checks should be held, bring this to a vote on the Senate floor,’” King said.

Schumer told reporters if McConnell brings the House bill to the floor, it would pass.

Republicans control 53 votes and 60 would be needed to clear the measure for Trump’s signature.

Schumer said Republicans will back the bill in the wake of the latest mass shootings, which are part of a pattern of similar attacks.

“I think the number will grow given what has happened in America in the last six months,” Schumer said, when asked about GOP support for the background check bill.

Current law requires background checks for gun purchases but Democrats believe loopholes exist that permit online buyers to escape the screening.

Gun-show purchases are not subjected to background checks.

King said the measure would ensure people who are not eligible to purchase guns, such as those with criminal backgrounds or domestic violence convictions.

“The fact is, one thing we know we can do and we can do quickly is pass this legislation,” King said. “It will save lives. It will make it harder and harder for people who are the most dangerous to obtain weapons.”

[Also read: The Trump gun trajectory: From banning assault weapons to NRA endorsement]