US president Joe Biden called for stronger gun laws as a Florida community remembered the 17 lives lost three years ago in 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.

There was no time to wait, the president said. He added: “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.”

Governor Ron DeSantis ordered flags be lowered to half mast from sunrise to sunset across the state to honour those who perished 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.

In his proclamation for a day of remembrance, DeSantis asked fellow Floridians to pause for a moment of silence at 3pm.

“The Parkland community is resilient in the wake of tragedy, reminding us just how strong and united Floridians can be in the face of such devastating loss,” the governor said in his proclamation.

The Republican governor also noted some of the school safety measures enacted since the tragedy three years ago, including money to install panic alert systems at schools across the state and to strengthen programmes meant to prevent violence before they occur.

Biden added in his statement: “We will take action to end our epidemic of gun violence and make our schools and communities safer.”

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