First lady Melania Trump has spoken out in support of the student movement pushing for gun reform after the deaths of 17 people in a high school gun massacre.

In her first public oration since revelations of an alleged affair between her husband Donald Trump and an adult actress became public in January, Mrs Trump said she was “heartened” by the rallies and outspoken calls for change by the Florida high school survivors.

“In my year as first lady, I have also learned that it is often times after a tragedy that you see strength and resilience of the human spirit,” she told the spouses of the nation’s governors in the Blue Room of the White House on Tuesday morning (AEDT).

“I have been heartened to see children across this country using their voices to speak out and try to create change. They are our future and they deserve a voice.”

Police say a 19-year-old-man used a semi-automatic AR-15 assault rifle to kill fellow-students and teachers at Marjory Stoneman Douglas High School this month.

First lady Melania Trump, speaking at a White House luncheon for governors' spouses in her first official public remarks of the year: “Our continued thoughts and prayers go out to all who were affected” by the Florida school shooting https://t.co/aGQ3Ydl87S pic.twitter.com/7rHs3OItJ0

— CNN (@CNN) February 26, 2018

School students across the United States have joined protests in support of the shooting survivors, calling for changes to the country’s gun laws.

Rallying under the banner of #NeverAgain, the students have directly attacked Mr Trump and the National Rifle Association (NRA) gun lobby over their stance on the availability of high powered rifles.

They have also made impassioned pleas to the government on television and are preparing a nationwide protest on March 24 dubbed “March for our Lives”.

The President has supported some reforms to the age at which Americans can buy high-powered weapons, but has aligned with the NRA in supporting the arming school staff as a solution to school mass shootings.

Mrs Trump also briefly spoke on Monday about issues affecting children, including cyberbullying.

“It is important that as adults we take the lead and the responsibility in helping our children manage the many issues they are facing today,” she said.

“This means encouraging positive habits with social media and technology, even limiting time online and understanding the content they are exposed to on a daily basis.”

Florida shooting survivor Lauren Hogg, 14, last week sent a direct tweet to Mrs Trump calling on her to look to her step son’s social media usage.

“Hey @FLOTUS you say that your mission as First Lady is to stop cyber bullying. Well then, don’t you think it would have been smart to have a convo with your step-son @DonaldJTrumpJr before he liked a post about a false conspiracy theory which in turn put a target on my back,” Ms Hogg tweeted.

Mr Trump Jr, the President’s eldest son, liked a tweet promoting a false conspiracy theory that claimed Ms Hogg’s older brother, David, had been coached by his father – a former FBI agent – to speak out against Mr Trump.

Hey @FLOTUS you say that your mission as First Lady is to stop cyber bullying, well then, don’t you think it would have been smart to have a convo with your step-son @DonaldJTrumpJr before he liked a post about a false conspiracy theory which in turn put a target on my back

— Lauren Hogg (@lauren_hoggs) February 23, 2018

Mrs Trump called on the governors’ spouses to promote kindness.

“I am asking you all to join me today and commit to promoting values such as encouragement, kindness, compassion, and respect in our children,” she said.

“With those values as a solid foundation, our kids will be better equipped to deal with many of the evils in our world today, such as drug abuse and addiction and negative social media interactions.”