Angela Merkel will miss the opening of the G20 summit after her plane to the event was forced to make an emergency landing.
The German Chancellor was travelling to Argentina for the leaders’ meeting before it was diverted back to Cologne, it was reported.
A "serious malfunction" forced her jet to make an unscheduled but safe landing on Thursday night.
German news agency dpa said the government Airbus turned around over the Netherlands about an hour into the 15-hour flight.
Mrs Merkel and German Finance Minister Olaf Scholz will resume their travel to Buenos Aires early on Friday, but the long flight time means they will arrive after leaders start their discussions.
She is set to meet with nineteen leaders of the world’s biggest economies at the summit in Buenos Aires, Argentina’s capital.
Among leaders attending the meeting, which starts on Friday, is US President Donald Trump.
Mr Trump confirmed earlier that he has cancelled his meeting with Vladimir Putin on the side lines of the event.
Explaining the cancellation, he blamed Russia’s seizure of Ukrainian vessels off Crimea on Sunday.
