WASHINGTON (AP) — President Donald Trump endorsed stricter gun-control measures Thursday, including raising the minimum age to 21 for possessing a broader range of weapons than at present. He tweeted his strongest stance as president one day after an emotional White House session where students and parents poured out wrenching tales of lost lives and pleaded for action.

Trump said on Twitter, "I will be strongly pushing Comprehensive Background Checks with an emphasis on Mental Health. Raise age to 21 and end sale of Bump Stocks!"

He did not immediately offer more details.

The current federal minimum age for buying or possessing handguns is 21, but the limit is 18 for rifles including assault-type weapons such as the AR-15 used by a former student in last week's attack on a Florida high school that killed 17 students and staff members.

A White House official said the president was not endorsing or ruling out any specific policy.

In another tweet, Trump repeated his urgent call for trained teachers or others in schools to carry guns as a deterrent to attacks.

"If a potential 'sicko shooter' knows that a school has a large number of very weapons talented teachers (and others) who will be instantly shooting, the sicko will NEVER attack that school. Cowards won't go there...problem solved. Must be offensive, defense alone won't work!" Trump tweeted.