Biden vows to strengthen gun laws in US

US President Joe Biden has called for stronger gun laws as he joined with the community of Florida to remember the 17 victims of a school shooting massacre.

Sorrow reverberated across America on Sunday on the three year anniversary of the Parkland school shooting massacre.

"In seconds, the lives of dozens of families, and the life of an American community, were changed forever," Biden said in a statement.

The president used the occasion to call on Congress to strengthen gun laws, including requiring background checks on all gun sales and banning assault weapons.

"We owe it to all those we've lost and to all those left behind to grieve to make a change. The time to act is now," he said.

Flags were lowered to half mast across Florida to honour those who died when a former student of Marjory Stoneman Douglas opened fire on campus with an AR-15 rifle on Valentine's Day in 2018.

When the gunfire ended, 14 students and three staff members were dead, and 17 others were wounded. The suspect, Nikolas Cruz, is still awaiting trial.

Biden said his administration would not wait until the next mass shooting to make change.

"We will take action to end our epidemic of gun violence and make our schools and communities safer," the president said.

In addition to background checks and an assault-weapons ban, Biden wants high-capacity magazines outlawed and to make gun manufacturers liable for the role their products play in violence.