WASHINGTON - U.S. President Donald Trump is refusing to rule out the possibility of another partial government shutdown to win congressional approval of funding for a wall along the southern border with Mexico. But he also signaled strongly he plans to declare a national emergency to build the barrier without assent from lawmakers.

"I don't take anything off the table," Trump told the CBS News show "Face the Nation" in an interview broadcast Sunday, a week after a record 35-day shutdown of a quarter of government operations was ended. "I don't like to take things off the table. It's that alternative."

Trump Won't Rule Out Another Shutdown in Border Wall Dispute

But the U.S. leader said, "It's national emergency, it's other things and you know there have been plenty national emergencies called. And this really is an invasion of our country by human traffickers."

Trump Won't Rule Out Another Shutdown in Border Wall Dispute

"These are people that are horrible people bringing in women mostly, but bringing in women and children into our country," he said. "Human trafficking. And we're going to have a strong border. And the only way you have a strong border is you need a physical barrier. You need a wall. And anybody that says you don't, they're just playing games."

Trump Won't Rule Out Another Shutdown in Border Wall Dispute

He assailed House Speaker Nancy Pelosi, leader of the Democratic-controlled House of Representatives, for continuing to oppose U.S. taxpayer-funding of the wall. Construction of the wall — and Mexico paying for it — was Trump's favorite 2016 campaign pledge during his successful run for the White House, but he now is calling for congressional approval of wall construction money.

"I think she [Pelosi] is very bad for our country," Trump said. "She knows that you need a barrier. She knows that we need border security. She wanted to win a political point. I happen to think it's very bad politics because basically she wants open borders. She doesn't mind human trafficking or she wouldn't do this."

Trump, ahead of the CBS interview that was taped Friday, had suggested he could announce that he is taking executive action to build the wall during Tuesday's annual State of the Union address before a joint session of Congress. But he also suggested he could also let a decision on the wall wait until Feb. 15, when funding runs out again for the Department of Homeland Security and other agencies that were shuttered.

A bipartisan congressional panel is negotiating over a border security plan, but opposition Democrats have so far offered no money for Trump's wall and he has called the border security discussions a waste of time. He wants $5.7 billion in wall funding, while Democratic lawmakers have offered more money for other border security provisions.

Trump said Pelosi is "costing the country hundreds of billions of dollars because what's happening is when you have a porous border, and when you have drugs pouring in, and when you have people dying all over the country because of people like Nancy Pelosi who don't want to give proper border security for political reasons, she's doing a terrible disservice to our country. And on the 15th we have now set the table beautifully" for an emergency declaration.

"She can keep playing her games, but we will win," Trump said. "Because we have a much better issue. On a political basis, what she's doing is — I actually think it's bad politics — but much more importantly it's very bad for our country."

Trump touched on a wide range of issues during the interview.

He questioned whether the U.S. should have invaded Afghanistan in 2001 under the administration of former President George W. Bush to destroy al-Qaida training grounds after the terrorist group's attacks on the U.S. killed nearly 3,000 people.

"Look, whether we should have been there in the first place, that's first question," Trump said.

Now, 18 years later, he said it was time for the U.S. to end its military operations in Afghanistan in a negotiated settlement with Taliban fighters opposing the Afghan government.

"I think they're tired and, I think everybody's tired," he said. "We got to get out of these endless wars and bring our folks back home. Now, that doesn't mean we're not going to be watching with intelligence. We're going to be watching, and watching closely. But, you know you pay a big price for troops on the ground. We're spending hundreds of billions of dollars on military. We're the policemen of the world."

He added, "We'll come back if we have to. We have very fast airplanes, we have very good cargo planes. We can come back very quickly, and I'm not leaving [the Middle East.] We have a base in Iraq and the base is a fantastic edifice."