The United States Senate defeated several measures to tighten gun control on Wednesday, dealing a strong blow to President Barack Obama's efforts to reform the nation's gun laws.

A bipartisan proposal to strengthen background checks was shut down in a 54 to 46 cloture vote, falling short of the 60-vote threshold for passage. Four Democrats voted no while all but four Republicans voted against it.

In other votes, just 46 senators backed a proposal limiting the size of ammunition magazines and only 40 supported the assault-weapons ban.

President Barack Obama released a statement, criticizing the Senate in what he called a "shameful day in Washington."