Presumptive Democratic presidential nominee Hillary Clinton appealed for calm Friday after Britain's stunning vote to leave the European Union, and said the first priority for the  United States should be to contain any economic fallout.

U.S. markets opened sharply lower on news of the British vote.

Clinton had backed the option of Britain remaining in the E.U., as did President Obama. Her campaign issued a statement in her name Friday morning that said nothing about the merits of the decision to leave.

"We respect the choice the people of the United Kingdom have made," Clinton said. "Our first task has to be to make sure that the economic uncertainty created by these events does not hurt working families here in America."

Sounding very much like her former secretary of state self, Clinton then spoke of the storied alliance between the United States and the United Kingdom, the "special relationship" that has made Britain America's strongest ally.

"We also have to make clear America's steadfast commitment to the special relationship with Britain and the transatlantic alliance with Europe," she said.

She then referred to the U.S. presidential election, with an implicit comparison of her own leadership with that of Republican opponent Donald Trump.

"This time of uncertainty only underscores the need for calm, steady, experienced leadership in the White House to protect Americans' pocketbooks and livelihoods, to support our friends and allies, to stand up to our adversaries, and to defend our interests," Clinton said.

That is essentially an appeal to stability and the comfort of the establishment status quo in time of powerful anti-establishment politics. As in Britain ahead of the Brexit vote, fears about immigration and frustration over government bureaucracy fueled the rise of outsider candidates in the United States this cycle.

Clinton withstood a strong populist challenge from Sen. Bernie Sanders (Vt.) in the Democratic primary this year, emerging from that clash between establishment and anti-establishment politics to face the populist outsider Trump. Trump supported the "leave" campaign in Britain.

Clinton is campaigning against Trump as the voice of experience and reason, while casting him as reckless, ill-informed and bigoted.

The British vote, Clinton said Friday, "underscores the need for us to pull together to solve our challenges as a country, not tear each other down."