"The president's weak executive order falls sadly and seriously short of what is required to combat the epidemic of racial injustice and police brutality that is murdering hundreds of Black Americans", the California Democrat said in a statement on Tuesday.
Trump, a Republican, opened his remarks by expressing sympathy to the families of victims of police violence, pledging to fight for justice, and promising them their loved ones will not have died in vain.
Trump's meeting and order comes as Trump has repeatedly called for "law and order" in the wake of weeks of demonstrations over George Floyd's death on Memorial Day, when a Minneapolis police officer knelt on Floyd's neck while he was under arrest.
"The president's going to take this action to assure the American people that we're listening, we're supporting law enforcement".
In his public comments and on Twitter, Trump has called for crackdowns on protesters and emphasized a forceful and militarized response to the social unrest sparked by the death of Floyd and others.
US President Donald Trump responded to nationwide anger at racism and deadly police violence Tuesday with measures aimed at reforming police forces, including a push to end risky choke holds during arrests.
USA opinion polls show there are widespread concerns among the public about brutal responses by law enforcement. It would ban chokeholds - except for when the police officer's life is at risk - and prioritize federal funding to departments that meet high standards on use of force and de-escalation training. It also would encourage them to use less-lethal weapons such as stun guns.
Trump also called for more funding for police departments, which he said in many cases are "underfunded, understaffed, and under-supported".
Democrats in the House of Representatives and Republicans in the Senate are preparing competing packages of policing changes as U.S. politicians seek to respond to mass demonstrations over the deaths of George Floyd and other Black Americans. Trump has repeatedly denounced the movement to "defund the police", and sought to tie Democratic presidential candidate Joe Biden to it, even though Biden has not embraced it.
"Today is about pursuing common sense and fighting for a cause like we seldom get the chance to fight for", Trump said.
Republican lawmakers are divided on that issue.
There was some positive reaction to Mr Trump's policy changes from police reform campaigners, especially over the new database and moves against chokeholds.
"I have a lot of skepticism in terms of how rigorously this is going to be implemented", she said.
Trump said the new order "a tremendous step toward safe, handsome and elegant justice", however, Democratic speaker of the House of Representatives, Nancy Pelosi slammed the order, saying: "The president's weak executive order falls sadly and seriously short of what is required to combat the epidemic of racial injustice and police brutality".