Sen. Roy Blunt (R-Mo.) on Thursday blocked the Senate from passing a bill to remove Confederate statues from the Capitol.

Senate Minority Leader Charles Schumer (D-N.Y.) and Sen. Cory Booker (D-N.J.) tried to pass the bill by unanimous consent, which allows legislation to pass without a vote but also enables any one senator to block it.

The measure would remove statues of individuals who voluntarily served in the Confederacy from the Capitol.

Booker called keeping statues of Confederate figures in the Capitol a "painful, insulting, difficult injury."

"The continued presence of these statues in the halls is an affront to African Americans and the ideals of our nation," he added.

Schumer added that passing a bill to remove the statues would be one step toward confronting the "poison of racism."

"Candidly, I don't think it would be too imposing to ask our states not to send statues of people who actively fought against this country. You know, there is a reason that Connecticut doesn't send a statue of Benedict Arnold," Schumer said.

But Blunt objected, noting that Congress had an agreement with states and that he wanted time to consider giving the issue a hearing in the Rules Committee, which he chairs.

"I'd like to ... get the opinion of people who are taking similar statues out of the building. I'd also like to find out what other states have in mind as their part of this agreement," Blunt said.

The presence of Confederate statues has emerged as a point of contention in the Capitol.

There are 11 statues of Confederate figures displayed in various quarters of the Capitol complex as part of the National Statuary Hall collection. Each of the 50 states contributes two statues to the collection, which they can replace if a change is approved by their state legislature and governor.

Democrats, including Speaker Nancy Pelosi (Calif.), are calling for the removal of Confederate statues. Pelosi said on Thursday that she had ordered the removal of four portraits in the Capitol of previous Speakers who served in the Confederacy.

"We didn't know about this until we were taking inventory of the statues and the curator told us that there were four paintings of Speakers in the Capitol of the United States, four Speakers who had served in the Confederacy," Pelosi told reporters in the Capitol.

But Republicans have warned that Congress cannot remove the statues without passing a new law, something GOP lawmakers have signaled they are not inclined to do, and said the decision should be left up to the states.

"What I do think is clearly a bridge too far is this nonsense that we need to airbrush the Capitol and scrub out everybody from years ago who had any connection to slavery," Senate Majority Leader Mitch McConnell (R-Ky.) told reporters on Tuesday when asked about an unrelated provision in a defense bill that would change Confederate-named military bases.

"You know, there were eight presidents who owned slaves. Washington did. Jefferson did. Madison did. Monroe did. Look, as far as the statues are concerned, every state gets two. Any state can trade out, as Sen. Blunt pointed out, if they choose to. And some actually are choosing to," he added.