Bipartisan congressional talks on overhauling policing practices have ended without an agreement, the top Democratic bargainer said Wednesday, marking an unproductive end to an effort that began after killings of unarmed Black people by officers sparked protests across the U.S.

“It was clear that we were not making the progress that we needed to make,” Sen. Cory Booker, D-N.J., told reporters. He cited continued disagreements over Democrats’ efforts to make officers personally liable for abuses, raising professional standards and collecting national data on police agencies’ use of force.

Booker said he’d told South Carolina Sen. Tim Scott, the lead Republican negotiator, of his decision earlier Wednesday.

Talks had moved slowly all year, and it had became clear over the summer that the chances for a breakthrough were all but hopeless.

A spokesperson for Scott did not immediately provide a comment on Booker’s remarks.

Reuters said that the White House was characterizing the breakdown as due to Republicans refusing to back police reform measures that former President Donald Trump himself had supported.

White House press secretary Jen Psaki was quoted as saying, “Unfortunately Republicans rejected reforms that even the previous president has supported and refused to engage on key issues that many in law enforcement were willing to address.”