The 23-year-old is in stunning form, remaining unbeaten in his last 13 races over one lap. Last week the American clinched the world title in Berlin with the fastest time of the year, clocking an impressive 44.06 seconds ahead of his compatriot Jeremy Wariner. The USA also claimed gold in the 4x400m relay ahead of Great Britain.
Now Merritt, who also won double gold at the Olympics last year, heads to Gateshead International Stadium hoping to make another big impression.
"I can’t wait to compete in Gateshead on Monday," Merritt said.
"I know the British love their athletics so I will put on a show for them for sure. The (London) Olympics are in three years’ time so I will be there in the UK to defend my title and the Diamond League is at Gateshead in 2010 so it will be good to try out the track.
"I’ve never raced at Gateshead but I know it has a history for long-distance running, hopefully I can create some new history in the 400m."
Merritt burst onto the scene when he set a world junior record in 2005, then emerged from Wariner’s shadow to take centre stage when he won gold in Beijing last summer – 0.99secs ahead of Wariner, which was the widest margin of victory since 1896.
The American star added: "To add the world title to my Olympic crown is an awesome feeling. I just turned 23 this past June, so there is hopefully more to come from me. I want to continue to get better and better throughout my career.
"My experience in Berlin was very rewarding – the crowds and the world records being broken all made it such a great week to be part of and to win double gold was of course the icing on the cake," he added.