Donald Trump said Tuesday night he would not let environmental concerns about snakes and toads get in the way of building 1,000 miles of wall on the U.S.-Mexico border.

The Republican nominee told Fox News' Sean Hannity he would begin construction of the wall "almost immediately."

"Now, if you would believe it, you know, they were going to build the wall a while ago, not so long ago. Like in '06. And they couldn't get environmental impact. Can you believe it? Now, we got lucky because it was such a little wall, it was such a nothing wall. They couldn't get it. Probably a snake was in the way or a toad," Trump told attendees at an Austin, Texas, rally.

Trump said animals and land issues will not interfere with his plan to improve national security. He also insisted Mexico will pay for the wall.

"It's so easy to do. And it gets higher and higher and higher every time somebody says I'm not going to do it," Trump said.

The GOP leader did not mention the logistical details Hannity had inquired about regarding the length of time it would take to secure the international boundary.

Hannity did not follow up with the same question, but redirected the interview to Trump's potential relationship as president with Mexico's government officials.

Donald Trump made it plain Tuesday night that he wouldn't let environmental concerns about snakes and toads stop him building his a wall at the Mexican border.

The GOP presidential candidate spoke on Fox News and said the wall would go up "immediately" if he is elected president.

Talking to host Sean Hannity, Trump said"Now, if you would believe it, you know, they were going to build the wall a while ago, not so long ago. Like in '06. And they couldn't get environmental impact. Can you believe it? Now, we got lucky because it was such a little wall, it was such a nothing wall. They couldn't get it. Probably a snake was in the way or a toad,"