US president Donald Trump kept largely silent about the Florida school shooting victims and the escalating gun control debate, instead raging at the FBI for what he perceived to be a fixation on the Russia investigation at the cost of failing to deter the attack.

From the privacy of Mar-a-Lago, Mr Trump vented about the investigation in a marathon series of tweets over the weekend.

He was last seen publicly on Friday night, when he visited the Florida community reeling from a school shooting that left 17 dead and gave rise to a student-led push for more gun control.

White House aides advised the president against golfing so soon after the tragedy, so Mr Trump spent much of the holiday weekend watching cable television news and grousing to club members and advisers.

On Sunday afternoon he met with Republican House Speaker Paul Ryan, discussing immigration, taxes, infrastructure and the Florida shooting, the White House said.

Amid a growing call for action on guns, the White House said on Sunday the president would host a "listening session" with students and teachers this week, but offered no details on who would attend or what would be discussed.

On Monday, 17 Washington students plan a "lie-in" by the White House to advocate for tougher gun laws. Students who survived the shooting at Marjory Stoneman Douglas High School in Parkland are planning a march on Washington next month to pressure politicians to take action on gun violence.

Throughout the weekend, the president's mind remained on Russia after an indictment from special counsel Robert Mueller on Friday charged 13 Russians with a plot to interfere in the US presidential election.

I never said Russia did not meddle in the election, I said âit may be Russia, or China or another country or group, or it may be a 400 pound genius sitting in bed and playing with his computer.â The Russian âhoaxâ was that the Trump campaign colluded with Russia - it never did! — Donald J. Trump (@realDonaldTrump) February 18, 2018

If it was the GOAL of Russia to create discord, disruption and chaos within the U.S. then, with all of the Committee Hearings, Investigations and Party hatred, they have succeeded beyond their wildest dreams. They are laughing their asses off in Moscow. Get smart America! — Donald J. Trump (@realDonaldTrump) February 18, 2018

Mr Trump viewed Deputy Attorney General Rod Rosenstein's declaration that the indictment did not show that any American knowingly participated as proof of his innocence, and was deeply frustrated that the media were still suggesting that his campaign may have colluded with Russian officials, according to a person who had spoken to the president in the last 24 hours.

Initially pleased with the Justice Department's statement, Trump has since griped that Rosenstein did not go far enough in declaring that he was cleared of wrongdoing, and grew angry when his national security adviser, HR McMaster, gave credence to the notion that Russia's meddling affected the election, the person said.

Mr Trump's frustration bubbled over on Twitter, where he stressed that the Russian effort began before he declared his candidacy, asserted that the Obama administration bore some blame for the election meddling and insisted he never denied that the Kremlin interfered in the 2016 US campaign.

He said late on Saturday that the FBI "missed all of the many signals" sent by the suspect and argued that agents were "spending too much time trying to prove Russian collusion with the Trump campaign".

The FBI received a tip last month that the man now charged in the school shooting had a "desire to kill" and access to guns and could be plotting an attack. But the agency said on Friday that agents failed to investigate.

PA Media