A bipartisan bill backed by President Barack Obama that would have expanded background checks on gun sales failed to pass in the U.S. Senate Wednesday.

Authored by Senator Joe Manchin, D-W.Va., and Senator Pat Toomey, R-Pa., the amendment required 60 of 100 votes to pass under an agreement by both parties. The final vote was 54 in favor, 46 against.

President Obama and others who backed the legislation cited the school shooting in Newtown, Conn., last December, the movie theater shooting in Aurora, Colo., over the summer and the 2011 attack on U.S. Rep. Gabrielle Giffords in Arizona as proof of the necessity of such legislation.

The president spoke about the failed amendment Wednesday afternoon at a press conference in front of the White House.

“Nobody could honestly claim that the package (Senators Manchin and Toomey) put together infringed upon our Second Amendment rights,” Obama said. “All it did was extend the same background check rules that already apply to guns purchased from a dealer, to guns purchased at gun shows or over the Internet.”

Obama said he was disappointed with the result of the vote but hopeful for the future.

“All in all, this was a pretty shameful day for Washington,” Obama said. “But this effort is not over.”