European, Asian and US markets fell today following immigration curbs introduced by Donald Trump.
The policies added to uncertainty as investors tried to predict the impact of the US president's policies.
Key markets in Europe, including the Paris CAC, Frankfurt DAX and London FTSE, fell by around 1%.
Major US stock indexes posted their largest drop so far in 2017 as investors worried that a curb on immigration ordered by Mr Trump was a reminder that some of the US president's policies are not market-friendly.
An executive order issued by Mr Trump on Friday banned immigration from seven Muslim-majority countries, including legal residents and visa holders, and temporarily halted the entry of refugees.
Over the weekend, thousands of people rallied in major US cities and at airports in protest.
US equities had hit a series of record highs following Mr Trump's election in November, encouraged by his promise of tax cuts and simpler regulations.
"Investors focused on the pro-growth of (Trump's) proposals and not those detrimental to economic activity, like protectionism," said Peter Cardillo, chief market economist at First Standard Financial in New York.
He said investors wore blinders to only see the market-friendly policies Mr Trump spoke about during the campaign and the immigration ban was a reminder of actions he could take that could undermine the economy.
Technology, a sector which has openly opposed bans on immigration and hurdles to hiring foreign talent, weighed the most on the S&P 500.
The Dow Jones Industrial Average fell 122.65 points, or 0.61%, to 19,971.13, the S&P 500 lost 13.79 points, or 0.60%, to 2,280.9 and the Nasdaq Composite dropped 47.07 points, or 0.83%, to 5,613.71.
It was the largest daily percentage drop for the Dow since October, while the S&P and Nasdaq dropped the most since late December.
