Anxious eyes will be on financial markets around the world, which reopen today after plummeting in the wake of the U.K.’s unexpected Brexit from the European Union that has one analyst predicting more “volatility” and “large declines.”

“There will be a lot of volatility throughout the whole week, this is not a one- or two-day event,” said Aaron Klein, with the Brookings Institution in Washington, D.C. “I expect a continued volatility, potential for large declines. … Britain’s decision to start the process of exiting the European Union, it’s an open question whether it’s an isolated incident or the first in a string of dominoes. Markets are having to adjust and readjust.”

The United Kingdom’s 52-48 percent referendum vote to bolt from the ?European Union roiled world markets, including Wall Street, where the Dow Jones industrial average shed more than 600 points, and left the British pound at its lowest level since 1985.

Britain’s Treasury said ?Finance Minister George Osborne would make an early morning statement ?today “to provide reassurance about financial and economic stability” ?before the London Stock Exchange ?reopens.

The leaders of the successful campaign to leave the EU stayed largely out of the public eye, as opponents ?accused them of lacking a plan to calm the crisis triggered by Brexit. In his first statement since Friday morning, “Leave” leader and former London Mayor Boris Johnson used his column in the Daily Telegraph newspaper to urge unity and wrote “the negative consequences (of the vote) are being wildly overdone.”

Britain would forge “a new and better relationship with the EU — based on free trade and partnership, rather than a federal ?system,” Johnson said.

In Rome, U.S. Secretary of State John F. Kerry urged Britain and the EU to manage their divorce responsibly for the sake of global markets and citizens.

Today Kerry will be the first senior U.S. official to visit London and Brussels since the referendum, and he said he would bring a message of U.S. support to both capitals.

The vote to exit the EU, however, risks causing a political schism in the United ?Kingdom. Thursday’s ?nationwide vote to leave the EU was very unpopular in Scotland, where 62 percent cast ballots to stay, and Scottish First Minister Nicola Sturgeon said she is studying ways to keep Scotland part of the EU bloc.

In Northern Ireland, Deputy First Minister ?Martin McGuinness said his priority is forging “special arrangements” to enable Northern Ireland to maintain its EU ties. Some Brexit opponents also have talked of trying to use Northern Ireland’s ?Assembly to try to block Britain’s departure.

Herald wire services ?contributed to this report.