• Heckle comes during rendition of Star-Spangled Banner

• US president has threatened tariffs on European nations

Mounting tensions between Europe and the United States moved into the sporting arena on Sunday when a member of the crowd shouted “Leave Greenland alone” as the US national anthem was sung during an NBA game in London.

Actor Vanessa Williams was performing the Star-Spangled Banner before the Memphis Grizzlies faced the Orlando Magic at the O2 Arena when she was interrupted by the heckle. The intervention drew a round of applause and cheers from sections of the crowd.