Follow CBSMIAMI.COM: Facebook | Twitter

MIAMI (CBSMiami) – In his first nationally-televised prime-time speech, President Donald Trump admitted he’s changed his mind on Afghanistan since taking office.

READ MORE: Coast Guard Offloads More Than Two Tons Of Seized Cocaine In Miami Beach

“My original instinct was to pull out. And, historically, I like following my instincts,” President Trump said, acknowledging his change of heart.

In a 2013 tweet, Trump urged the U.S. to get out of Afghanistan, calling it a waste of money.

Now he believes a hasty withdrawal would be disastrous.

“Our nation must seek an honorable and enduring outcome,” he said.

America’s longest war is not President Trump’s war.

The U.S. sent troops to Afghanistan in 2001, following the September 11th terror attacks.

Fighting insurgents and mentoring and supporting afghan forces since 2002 has cost more than 2,400 American military lives and has left more than 20,000 wounded.

Still, Taliban forces continue to control a large number of key territories. It’s why the president is looking to frame this in national security terms.

“We are not nation building again, we are killing terrorists,” he said.

The president talked about a new military approach that would be based on conditions on the ground, not on timetables.

READ MORE: Authorities Arrest Broward Schools Superintendent Robert Runcie On Perjury Charge

He would not reveal if or how many additional troops he might send to the region.  There are currently close to 10,000.

“America will work with the Afghan government as long as we see determination and progress,” he said. “However, our commitment is not unlimited and our support is not a blank check.”

President Trump made his Afghanistan decision without former Chief Strategist Steve Bannon who was fired on Friday.

It was Bannon who urged the president to send paid mercenaries instead of troops to Afghanistan.

Florida Sen. Bill Nelson, who sits on the Senate Armed Services Committee, released a statement following the president’s speech.

“In the short run, the Afghan government has been overrun by terrorists and needs to be strengthened temporarily. In the long run, the Afghans must protect their own people and the U.S. troops should exit the country as soon as practical.”

Sen. Marco Rubio tweeted his support.