Utilize the input text as a context reference, choose the right relationship between 'Donald Tusk' and 'President of the European Council' from the options.
Options: position held, creator, brand, distribution format

LUXEMBOURG, July 9 National parliaments should be convinced to vote in favour of helping Greece if European leaders can reach a good agreement on Sunday, President of the European Council Donald Tusk said, adding that a deal on debt should be part of the agreement.
position held