LONDON, Jan 18 - Global markets face a fresh bout of volatility this week after President Donald Trump vowed to slap tariffs on eight European nations until the U.S. is allowed to buy Greenland.

Trump said he would impose an additional 10% import tariffs from February 1 on goods from Denmark, Norway, Sweden, France, Germany, the Netherlands, Finland and Britain, which will rise to 25% on June 1 if no deal is reached.