European Commission President Ursula von der Leyen is in the running to be the new head of Nato, The Sun newspaper reported, citing a diplomatic source.
A number of Nato member states have suggested von der Leyen would take over the alliance this October, the report said.
Nato's current secretary-general Jens Stoltenberg is expected to end his term as planned in October, after his mandate has been extended three times and having served for a total of almost nine years.
The Sun report, citing UK sources, also said Britain would likely veto von der Leyen, who was the former German defence minister, citing her poor track record in charge of Germany's armed forces.
German newspaper Welt am Sonntag has reported that Spain's prime minister Pedro Sanchez and Britain's defence secretary Ben Wallace were among the leading candidates to succeed Stoltenberg.
