"We building a school, we build a road, they blow up the school, we build another school, we build another road -- they blow them up," Trump said.
"Meanwhile, we can't get a f---ing school in Brooklyn."
Trump did not mince words when proposing how best to deal with trading with the Chinese, saving his most profane language for that issue.
"Listen you mother---ers, we're going to tax you 2percent," he said.
Trump earlier this week visited the early primary state of New Hampshire. On Saturday he will attend the White House Correspondents Dinner as a guest of the Washington Post.
Rhona Graff, Trump's spokeswoman, told ABCNews.com she had "no comment" about Trump's Selective Service history or the comments he made in Las Vegas.
Trump has said he will not announce whether he will seek the Republican nomination until the current season of his show "The Celebrity Apprentice" concludes later in May.