Here's a review of what Trump has said about U.S. policy in Afghanistan in the past.
Before his presidential campaign
Trump was active on social media, particularly on Twitter, long before he ran for president.
In 2011, he suggested it was a matter of priorities, writing, "When will we stop wasting our money on rebuilding Afghanistan? We must rebuild our country first."
In 2012, he called the conflict a "total disaster" said, "we don't know what we are doing," and later criticized the Afghan forces.
"Afghanistan is a total disaster. We don't know what we are doing. They are, in addition to everything else, robbing us blind," he wrote in March 2012.
Five months later, Trump wrote, "Why are we continuing to train these Afghanis who then shoot our soldiers in the back? Afghanistan is a complete waste. Time to come home!"
The following year, he echoed his earlier sentiments.
"Let’s get out of Afghanistan. Our troops are being killed by the Afghanis we train and we waste billions there. Nonsense! Rebuild the USA," he wrote in January 2013.
Later that year, he appeared dismayed about the prospect of keeping 20,000 troops "there for many more years," adding the next day, "We have wasted an enormous amount of blood and treasure in Afghanistan."
"Do not allow our very stupid leaders to sign a deal that keeps us in Afghanistan through 2024-with all costs by U.S.A. MAKE AMERICA GREAT!" he wrote on Nov. 21, 2013.
In late 2014, Trump took issue with then-President Obama's decision to keep American soldiers on the ground in Afghanistan for another year. "He is losing two wars simultaneously," Trump wrote.
During the campaign
One of the most controversial statements Trump made about Afghanistan came during an October 2015 interview with CNN.
"We made a terrible mistake getting involved there in the first place," he said on CNN's "New Day" on Oct. 6, 2015.
"At some point, are they going to be there for the next 200 years? At some point what's going on? It's going to be a long time," he said.
"We made a terrible mistake getting involved there in the first place. We had real brilliant thinkers that didn't know what the hell they were doing. And it's a mess. It's a mess. And at this point, you probably have to (stay) because that thing will collapse about two seconds after they leave. Just as I said that Iraq was going to collapse after we leave."
Later that same month, Trump said that he never said that the U.S. should not have gone into Afghanistan in the first place, asserting that he was talking about Iraq. Trump often claimed that he had always been against the invasion of Iraq, which is not supported by evidence.
"We made a mistake going into Iraq. I've never said we made a mistake going into Afghanistan," he said.
The presidential candidate maintained that explanation when asked during a March 3, 2016, Republican debate about a series of flip-flops he had made about Afghanistan.
"It is carnage. It's horrible carnage. This is Afghanistan -- is not like what's happening in Chicago. People are being shot left and right," he said, referring back to a point in his inaugural speech when he talked about "American carnage."
Trump and his team have since been developing the administration's policy for Afghanistan.
Defense Secretary Mattis told Congress in June that he believed the administration would formulate its Afghanistan strategy by mid-July. But that deadline came and went because Trump's national security team debated whether the strategy should be broader in scope.
The plan for Afghanistan has evolved into what is now known as the South Asia strategy and includes regional considerations for neighboring countries like Pakistan, India, China and Russia.
Trump is said to have been dissatisfied with the original strategy review and the request for more American troops, which is one reason why his national security team has developed additional options.
Trump most recently met with his national security team on Aug. 18, 2017, and tweeted the following day that there were "many decisions made, including on Afghanistan."
ABC New's Luis Martinez and Alexander Mallin contributed to this report.