Hillary Clinton takes a swipe at Donald Trump over Brexit

Democrat Hillary Clinton took a swipe at Republican rival Donald Trump's stance on Brexit, saying that "bombastic comments" do more harm than good during such times.

Trump has hailed Britain's vote to leave the European Union as "fantastic," telling reporters during a visit to Scotland on Friday that he thinks the Brexit is "a great thing."

Clinton, who was speaking to the US Conference of Mayors, did not mention Trump by name, but told city leaders that the United States should be governed by those "who put the interest of the American people ahead of their personal business interests."

Trump was in Scotland for the ceremonial re-opening of his refurbished Trump Turnberry golf course.

America needs leaders "who understand that bombastic comments in turbulent times can actually cause more turbulence," Clinton said.

"And that's why steady, experienced leadership is so important at times like these."

Trump, who has relied on populist fervor and anti-immigrant rhetoric in his presidential bid, has said Britain's anti-EU movement had parallels with his own quest to become the US president.

Clinton acknowledged on Sunday that "just as we have seen there are many frustrated people in Britain, we know there are frustrated people here at home too."

But, she told the mayors who gathered in the midwestern city of Indianapolis, "no one should be confused about America's commitment to Europe, not an autocrat in the Kremlin, not a presidential candidate on a Scottish golf course."

New polls released on Sunday showed Clinton taking a lead in the presidential race. According to a Washington Post-ABC News survey, 51% of respondents said they would vote for Clinton, versus 39% for Trump.

A Wall Street Journal/NBC News poll showed a slimmer lead for Clinton with 46% to Trump's 41%.