WASHINGTON (Reuters) - U.S. Republican presidential candidate Donald Trump, reacting to attacks at Brussels airport and a metro station on Tuesday, said the United States and Western countries should toughen up in their fight against Islamist militants.

"I would close up our borders," Trump told Fox News in an interview.

"We are lax and we are foolish," said Trump, the front-runner in the race for the Republican nomination in the November election.

(Reporting by Washington Newsroom; Editing by Chizu Nomiyama)