Americans Dustin Johnson and Zach Johnson both pulled out of this week's Ballantine's Championship it was announced on Monday.
Tournament organizers said in a statement, "Ballantine's is disappointed to announce that Dustin Johnson and Zach Johnson have informed us they will no longer be attending the Ballantine's Championship. They have reached this decision following perceived unrest on the Korean Peninsula and can no longer assure their commitment to this year's event."
Dustin Johnson played in the tournament in 2011 and took fourth place. Zach would have been competing in the event for the first time.
Two weeks ago at the Masters, Dustin Johnson shared 13th place for his third straight top-15 finish on the PGA Tour. Outside the majors and World Golf Championship events, his last appearance on the European Tour was last October at the Alfred Dunhill Links Championship.
This tournament would have marked Zach Johnson's first European Tour start outside the majors and World Golf Championship events. Zach Johnson has played the last two PGA Tour events, and has just one top-20 finish in 10 tour starts this season.
Despite their withdrawal, the tournament will go on with the likes of Louis Oosthuizen, Y.E. Yang, Paul Lawrie, Thomas Bjorn, Thongchai Jaidee, Marcus Fraser and Paul Casey headlining the field.