US president Donald Trump said he is "watching court cases and rulings" before taking action on raising age limits for purchasing some firearms, arguing that there is "not much political support (to put it mildly)".
Mr Trump's tweet came after the White House put forward a plan to combat school shootings that does not increase the minimum age for purchasing assault weapons to 21 - an idea the US leader publicly favoured just last month - and leaves the question of arming teachers to states and local communities.
Instead, a new federal commission on school safety will examine the age issue as part of a package the White House announced on Sunday in response to the school shooting in Parkland, Florida, last month which left 17 people dead.
At a rally in Pennsylvania on Saturday, Mr Trump criticised policy commissions while speaking about the opioid problem, saying: "We can't just keep setting up blue-ribbon committees."
On Twitter today, Mr Trump described the school shooting effort as a "very strong improvement" and said: "Armed guards OK, deterrent!"
Very strong improvement and strengthening of background checks will be fully backed by White House. Legislation moving forward. Bump Stocks will soon be out. Highly trained expert teachers will be allowed to conceal carry, subject to State Law. Armed guards OK, deterrent!.......— Donald J. Trump (@realDonaldTrump) March 12, 2018
On age limits, he said: "Watching court cases and rulings before acting. States are making this decision. Things are moving rapidly on this, but not much political support (to put it mildly)."
....On 18 to 21 Age Limits, watching court cases and rulings before acting. States are making this decision. Things are moving rapidly on this, but not much political support (to put it mildly).— Donald J. Trump (@realDonaldTrump) March 12, 2018
The president quickly drew Democratic criticism over age limits. Senator Richard Blumenthal tweeted that Mr Trump "couldn't even summon the political courage to propose raising the age limit on firearm purchases - despite repeated promises to support such a step at a meeting with lawmakers".
Shamefully, the President couldn’t even summon the political courage to propose raising the age limit on firearm purchases - despite repeated promises to support such a step at a meeting with lawmakers.— Richard Blumenthal (@SenBlumenthal) March 12, 2018
For now, the White House is backing a modest background checks bill and a school safety measure, which are both expected to have widespread bipartisan support, even though some Republicans object and many Democrats say they are insufficient.
Republican Senator Orrin Hatch of Utah, who wrote the school safety bill, tweeted he was "grateful" for the White House backing, calling the measure "the best first step we can take" to make students safer.
The president also repeated his criticism of keeping guns out of schools, tweeting: "If schools are mandated to be gun free zones, violence and danger are given an open invitation to enter. Almost all school shootings are in gun free zones. Cowards will only go where there is no deterrent!"
The administration also pledged to help states pay for firearms training for teachers and reiterated its call to improve the background checks and mental health systems.
Education secretary Betsy DeVos declined to say how many teachers should be armed.
"This is an issue that is best decided by local communities and by states," she said on NBC. "It's not going to be appropriate in every location, but it is going to be appropriate in some places."
The plan was immediately panned by gun control advocates, including the Brady Campaign to Prevent Gun Violence.
"Americans expecting real leadership to prevent gun violence will be disappointed and troubled by President Trump's dangerous retreat from his promise," said Avery Gardiner, the group's co-president.