US President Donald Trump has signed an executive order on policing amid calls for action against police brutality and racism.

It comes three weeks after the death of George Floyd, a 46-year-old African American man, in police custody in Minneapolis, Minnesota, which has triggered nationwide demonstrations.

The executive order signed on Tuesday focuses on three areas: credentialing and certifying police officers; boosting information sharing to track officers accused of excessive use of force; and creating co-responder programs on mental health, drug addiction, and homelessness, Xinhua reported.

It also said police departments must "prohibit the use of chokeholds -- a physical maneuver that restricts an individual's ability to breathe for the purposes of incapacitation -- except in those situations where the use of deadly force is allowed by law."

Trump, speaking at the White House before signing the executive order, stressed that he "strongly" opposes efforts to defund or dismantle police departments, calling the ideas "radical."

"Without police, there is chaos. Without law, there is anarchy and without safety, there is catastrophe," he said.

The move from the White House comes alongside separate efforts on Capitol Hill focused on police reforms.

The Democrat-led House introduced a bill last week that aims to ensure officers can be held accountable for misconduct and increase transparency. The Republican-led Senate is also creating its own legislative package that will focus on police reporting, accountability, training and relations.

Chuck Schumer, the Senate minority leader, said on Tuesday that Trump's executive order is not enough.

"While the president has finally acknowledged the need for policing reform, one modest executive order will not make up for his years of inflammatory rhetoric and policies designed to roll back the progress made in previous years," Schumer said in a statement.

"Unfortunately, this executive order will not deliver the comprehensive meaningful change and accountability in our nation's police departments that Americans are demanding," the New York Democrat added. "Congress needs to quickly pass strong and bold legislation with provisions that makes it easier to hold police officers accountable for abuses, and President Trump must commit to signing it into law."

Floyd died during an arrest in Minneapolis, Minnesota late last month after a white police officer kneeled on his neck for nearly nine minutes.

Protests in response to Floyd's death, and more broadly to police violence, spread across the United States and took place in some other countries.