Republican presidential nominee Donald Trump at a town-hall-style forum on Thursday in Sandown, New Hampshire. AP Photo/Robert F. Bukaty Donald Trump has suggested that an "attack first" strategy might be best when confronting America's enemies.

During a town-hall event in Sandown, New Hampshire, on Thursday, the Republican presidential nominee expressed contempt for Hillary Clinton's plan to fight terrorist groups like ISIS.

Clinton, the Democratic nominee, has proposed supply-line disruptions and increased airstrikes to drive ISIS militants out of key areas of Iraq and Syria.

Trump, who has been criticized for refusing to publicly discuss details of his campaign's antiterrorism proposals, asked on Thursday: "Isn't there an element of surprise?"

"Remember when we were young and we were studying history, and they talk about some of the great generals, and the great attacks? ... Wouldn’t it be nice if we attacked first, and talked about our great victory later?" the GOP nominee added.

"It's a very, very sad thing. We are being run by people that are incompetent."

Clinton, who served as secretary of state during President Barack Obama's first term, has criticized Trump for not outlining the specifics of his plans to fight terrorism. At the candidates' first debate, she said, "He says it's a secret plan, but the only secret is that he has no plan."

Watch the full video of Donald Trump's town hall meeting below: