Bipartisan negotiations in the US Congress over a police reform bill that was prompted by the killing of George Floyd have collapsed.

“We did the best we could,” the Democratic congresswoman Karen Bass told reporters on Wednesday.

The House passed the George Floyd Justice in Policing Act in March, and Bass and the Democratic senator Cory Booker have since been working with the Republican senator Tim Scott to try to reach a bipartisan agreement on a bill that could pass the Senate.

But the talks dragged on for months with negotiators remaining at odds over a few crucial issues in the bill, and the lawmakers now appear to have thrown in the towel.

Most notably, the bipartisan negotiating team could not reach an agreement on the Democratic proposal to reform qualified immunity, which shields police officers from civil liability for misconduct.

“We made it clear from the beginning of our negotiations that a bill must ensure true accountability, transparency and the policing standards necessary to bring an end to horrific incidents of violence Americans are routinely seeing – like the murder of George Floyd,” Booker said in a statement on Wednesday.

“After months of exhausting every possible pathway to a bipartisan deal, it remains out of reach right now,” he added.

Bass said the negotiations with Scott had negatively affected the police reform bill to the point that the legislation would not have made a meaningful impact.

“We accepted significant compromises, knowing that they would be a tough sell to our community, but still believing that we would be moving the needle forward on this issue,” Bass said in a formal statement.

“But every time, more was demanded to the point that there would be no progress made in the bill that we were left discussing.”

The sweeping legislation passed by the House would have banned chokeholds and qualified immunity for law enforcement and would have created national standards for policing in an effort to increase accountability. Floyd, a 46-year-old Black man, was killed by a white Minneapolis police officer in May 2020, setting off mass anti-racism protests that called for widespread police reform.

However, the only Republican who voted in favor of the House bill at the time said he did so in error, and later changed the official record to reflect his opposition.

Now that the negotiations have collapsed, Bass called on Joe Biden and his administration to “use the full extent of their constitutionally mandated power to bring about meaningful police reform”.

“Our sense of urgency remains, but this issue requires a re-engagement of the legislative process,” Bass said.

“With our counterparts unwilling to come to a compromise, we have no other option than to explore further avenues to stop police brutality in this country. I will not ask our community to wait another 200 days.”

Scott had repeatedly insisted in recent months that there was still hope for a deal on the police reform bill.

Joe Biden said he will consider “potential further executive actions” to address police reform after the bipartisan team of congressional negotiators failed to reach a deal on a bill.

“The murder of George Floyd is a stain on the soul of America,” the president said in a new statement addressing the collapse of the negotiations. “It spurred the nation to collectively demand justice, and we will be remembered for how we responded to the call.”

“Regrettably, Senate Republicans rejected enacting modest reforms, which even the previous president had supported, while refusing to take action on key issues that many in law enforcement were willing to address,” Biden said.

Biden noted he still hoped to sign police reform legislation, but he said he would soon explore additional steps to determine what executive action he may be able to take on the issue.

“In the coming weeks, we will continue to work with Senator Booker, Congresswoman Bass and other members of Congress who are serious about meaningful police reform,” Biden said.

Meanwhile, the civil rights attorneys Ben Crump and Antonio Romanucci, who have represented the family of George Floyd, expressed “extreme disappointment” over the collapse of police reform talks in Congress.

“In the last year and a half, we have witnessed hundreds of thousands of Americans urging lawmakers to bring desperately needed change to policing in this country so there can be greater accountability, transparency and ultimately trust in policing,” the lawyers said in a statement.

“We can not let this be a tragic, lost opportunity to regain trust between citizens and police.”

Crump and Romanucci urged Senate Democrats to bring the George Floyd Justice in Policing Act, which passed the House in March, to the floor “so Americans can see who is looking out for their communities’ best interests”.

Associated Press contributed to this report