The White House says President Donald Trump supports efforts to improve federal background checks for gun purchases, days after a shooting at a Florida school killed 17 people.

Mr Trump spoke to Republican Senator John Cornyn on Friday about a bipartisan bill that he and Democratic Senator Chris Murphy introduced to improve federal compliance with criminal background checks, White House spokeswoman Sarah Huckabee Sanders said in a statement Tuesday morning (AEDT).

“While discussions are ongoing and revisions are being considered, the President is supportive of efforts to improve the federal background check system,” Ms Sanders said.

Previous mass shootings in the United States have also stirred outrage and calls for action to tighten US gun laws, with few results in congress.

Students are mobilising around the country in favour of stronger gun laws after the deadliest high school shooting in US history took place on Wednesday at Marjory Stoneman Douglas High School, where a former student is accused of murdering 17 people using an assault-style rifle.

Mr Trump, who visited survivors of the shooting and law enforcement officials on Friday night, is a strong supporter of gun rights and won the endorsement of the National Rifle Association, the powerful gun lobby group, for his 2016 presidential campaign.

Many Republicans generally oppose measures to tighten gun restrictions, citing the US Constitution’s Second Amendment protection of the right to bear arms.

Former president Barack Obama and many of his fellow Democrats unsuccessfully pushed to pass gun control legislation after a shooter killed 20 young children and six adults at Sandy Hook Elementary School in Newtown, Connecticut, in 2012.

Mr Cornyn and Mr Murphy introduced their bill to improve federal background checks last November, days after a gunman killed more than two dozen people in a church in Texas.

The bill, called the Fix NICS Act, would ensure that states and federal agencies comply with existing law on reporting criminal history records to the national background check system.

Mr Cornyn, of Texas, complained when introducing the legislation that compliance by agencies was “lousy”.

Nikolas Cruz, 19 was arrested by police after allegedly killing 17 people at his former school. Photo: Twitter

Students are planning a “March For Our Lives” protest in Washington on March 24 to call attention to school safety and ask lawmakers to enact gun control.

Some students reacted with caution to Mr Trump’s support on background checks.

“We want to prevent mass shootings from happening and while this could have happened with other types of weapons, #NeverAgain believes school safety should be priority right now, not just background checks,” said Marjory Stoneman Douglas High School student Kali Clougherty, 18, referring to a campaign for gun control.

“This is about the victims. Don’t forget that, we never will.”

-Reuters