U.S. President Donald Trump has described Afghanistan as a “lab for terrorists,” saying in a television interview that if the United States withdraws its military forces from the country, he would still leave a “very strong intelligence” presence behind.

"I call it the Harvard of terrorists," Trump said about Afghanistan and referring to the prestigious private Ivy League research university in Cambridge, Massachusetts.

Trump made the remarks in an interview conducted during the weekend with Fox News that was broadcast on July 1.

The interview was recorded before a truck bomb attack by Taliban fighters in Kabul on July 1 that killed at least six people and wounded 105.

It was broadcast after U.S. special peace envoy Zalmay Khalilzad met on July 1 for a seventh round of peace talks with Taliban representatives in Qatar.

The focus of the talks has been a Taliban demand that foreign forces leave Afghanistan and a U.S. demand for a guarantee that Afghanistan will not be used as a base for attacks elsewhere.

Trump told Fox News he wants to pull U.S. troops out of Afghanistan.

But he said he is concerned that without a U.S. military presence there, Afghanistan could be used as a base for terrorist attacks on the United States.

He described conversations he had with U.S. military officials who warned him it would be better to fight terrorists in Afghanistan than at home.

"'Sir, I'd rather attack them over there, then attack them in our land,'" Trump said one general had told him.

"It's something you always have to think about," Trump said about the general’s remarks.