'ISIS is falling fast,' Trump remarks before entering Pentagon meeting

• President Donald Trump held a top-level meeting at Pentagon to discuss anti-ISIS efforts in Iraq and Syria as well as Afghanistan.
• Trump was upbeat on ISIS fight but when asked about possible new troop deployments to Afghanistan he responded, "We'll see."
• After the meeting, the Chairman of the Joint Chiefs of Staff and the secretaries of Defense and State briefed House members on the ISIS fight.

President Donald Trump greets members of the US military alongside Defense Secretary James Mattis (C) following a meeting at the Pentagon in Washington, DC, July 20, 2017.

Saul Loeb | AFP | Getty Images

The battle being waged against Islamic State is going "very well" and the terrorist group is "falling fast," President Donald Trump said Thursday.

The top-level national security meeting lasted about two hours and is believed to have covered everything from the ongoing war in Afghanistan to the battle against ISIS, or the Islamic State in Syria and Iraq.

One of the topics believed to have been discussed is whether to send thousands of new U.S. troops to fight in Afghanistan.

When asked by reporters about whether more troops would be deployed, Trump responded, "We'll see," according to NBC News. He also was upbeat on the fight against ISIS: "We're doing very well against ISIS. ISIS is falling fast. Very fast."

The list of people in the room for Thursday's meeting included Vice President Mike Pence, Defense Secretary James Mattis, Joint Chiefs of Staff Gen. Joseph Dunford, Secretary of State Rex Tillerson and Treasury Secretary Steven Mnuchin.

After the meeting, Mattis, Tillerson and Dunford traveled to Capitol Hill where they gave a classified briefing on the ISIS campaign to members of the House. It followed a similar briefing provided to the Senate on Wednesday.

Last month, the president gave Mattis the authority to send more service members to Afghanistan.

The defense secretary is believed to be close to authorizing up to an additional 5,000 new troops to Afghanistan, which would be a significant increase from the current level of nearly 8,400 U.S. troops.

A Pentagon spokesman said Thursday there's no firm date on a decision.

NATO member nations also could be close to sending more troops to Afghanistan to fight against the Taliban, which, after 15 years of conflict, remains a formidable insurgent group. The Taliban is estimated to have more than 50,000 fighters and controls large swaths of Afghan territory.

Another destabilizing force in Afghanistan is increasing violence from an affiliate of ISIS. Last week, the U.S. military confirmed it killed the leader of the ISIS affiliate.

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