Merz presents US president with grandfather's birth certificatepublished at 18:15 British Summer Time 5 June
Bernd Debusmann Jr
Reporting from the White House

Just a few minutes ago, we saw Merz present Trump with the birth certificate of his grandfather.
But just who was Friedrich Trump?
We know that Trump's grandfather in 1869, in the Bavarian town of Karllstadt, which was then part of the Kingdom of Bavaria.
He emigrated to the US in 1885 - reportedly to avoid mandatory military service - and settled at first in New York, which at the time was seeing a large influx of German immigrants.
A few years later, he headed west during the Klondike Gold Rush to Canada's Yukon Territory, running restaurants and hotels that catered to gold miners.
He later returned to in 1901, but was expelled and returned to the US with his then now-wife, Elisabeth Christ.
There, he began setting up the real estate empire that made the family famous and which later expanded by his son Fred - the president's father.
Friedrich Trump died in 1918 during the Spanish Flu pandemic. Fred was three years old.