WASHINGTON (CBSNewYork/AP) — President Barack Obama said the U.S.-led campaign to against the Islamic State group continues to be a difficult fight, but significant progress is being made.

More than 120 top Islamic State leaders and commanders have been “taken out” and the group has lost nearly half of populated territory it once controlled in Iraq, the president said after meeting with his National Security Council. Tuesday’s gathering of top officials at the Treasury Department was scheduled before Sunday’s mass shooting.

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“Our message is clear: If you target America and our allies, you will not be safe, you will never be safe” he said.

Obama said there is no information indicating that a foreign terrorist group directed the attack in Orlando and it is increasingly clear that shooter Omar Mateen took in extremist information and propaganda over the internet.

“He appears to have been an angry, disturbed, unstable young man who became radicalized,” the president said.

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Obama was also briefed on the effort to prevent what the White House describes as “lone wolf” attacks. He said thwarting those attacks is as difficult as fighting the Islamic State in the battlefield in Iraq and Syria.

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“These lone actors or small cells of terrorists are very hard to detect and very hard to prevent but across our government at every level — federal, state and local, military and civilian — we are doing everything in our power to stop these kinds of attacks,” Obama said.

In speaking about the victims of Sunday’s attack, the president said “they are not alone.”

“The American people, our allies, friends, people all over the world stand with them,” he said.

Meanwhile, the president is challenging Congress to reinstate the assault weapons ban and make it harder for terrorist to kill Americans. The ban on semi-automatic assault weapons expired in 2004. The large majority of Republicans in Congress and some pro-gun Democrats have opposed reinstatement of the ban.

Democrat Hillary Clinton has called for a similar ban, while Republican Donald Trump is opposing reinstatement of the ban.

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