Almost 20 EU countries nominated Dr Tedros Adhanom Ghebreyesus for a second term as Director General of the World Health Organisation, shortly before the deadline passed on Thursday.
WHO member states had until 4pm GMT to nominate candidates for the May 2022 election.
Germany said on Wednesday that it was proposing Dr Tedros, 56, who appears to be the only candidate, and was supported by France.
Other EU nations followed Berlin's lead and backed the Ethiopian former health and foreign minister, diplomatic sources told AFP.
Each country, also including Austria, Portugal and Spain, submitted a sealed envelope to the WHO in Geneva.
The organisation will not open the envelopes before October 1. A few weeks later, the list of candidates will be sent to the WHO's 194 member states, before being made public.
In 2017, Dr Tedros became the first African to head the powerful UN agency.
He has been on the front line since the start of the Covid-19 crisis, making him one of the most familiar faces in the fight against the pandemic.
Dr Tedros declined to confirm he was running for a second term.
His nomination by European countries comes as a surprise, because most observers predicted that official support would come from African nations.
Dr Tedros is fairly popular because of his role in steering the WHO's efforts to co-ordinate the global pandemic response.
But his candidacy became complicated after Ethiopia allegedly withdrew its support because of the conflict in his home region of Tigray.
Candidates for the UN health body's top slot are generally nominated by their home countries.
Dr Tedros drew the ire of Addis Ababa by using the WHO platform to condemn the crackdown in Tigray.
If more candidates come forward, a selection process will start in January 2022 to establish a shortlist of up to five possible directors general.
Member states will vote for the next head of WHO, whose term begins in August next year, in a secret ballot in May during the World Health Assembly, the WHO's main annual meeting of member states.
