Fears over the post-Brexit economy have extended as far as the United States, with Barack Obama saying there "longer-term concerns about global growth".
Speaking from the North American Leaders' Summit in Ottawa, Canada, the US president said there had been reactions in the market, stock prices and currencies following the UK's vote to leave the EU.
He added that they were "monitoring very carefully whether there is any systemic strains on the system".
"I think the preparations that were done by central banks, and finance ministers, our treasury secretary - indicate the degree to which the global economy, in the short run, will hold steady," he said.
"I think there are some genuine longer-term concerns about global growth - if in fact Brexit goes through and that freezes the possibilities of investment in Great Britain or in Europe as a whole.
"At a time when global growth rates were weak already, this does not help."