Novak Djokovic will play in the ATP Cup, organizers say, after weeks of uncertainty.

The No. 1-ranked tennis player Novak Djokovic will participate in the ATP Cup in Sydney, Australia, in January, the tournament’s organizers said on Tuesday. The announcement came after weeks of speculation about whether Djokovic would travel to Australia for the Australian Open Grand Slam because of vaccine requirements.

The ATP Cup announced that Djokovic would play on the Serbian team in the tournament, which will take place during the first nine days of the month. The cup is a precursor to the Australian Open, which will be held in Melbourne from Jan. 17 to Jan. 30. It is still unclear if Djokovic will be taking part in that competition, however. He could not immediately be reached for comment.

Australia has placed a temporary two-week ban on international arrivals because of the Omicron variant. Before that, the government announced that some categories of visa holders would be allowed to freely enter the country if they were vaccinated. Officials placed caps on the number of unvaccinated travelers who could enter the country per week, and they were required to quarantine for two weeks upon arrival.

In October, Djokovic, the reigning champion and a nine-time winner of the Australian Open, told a Serbian news outlet that he might not attend the Australian Open because he would not reveal his vaccination status.

Daniel Andrews, the premier of Victoria, the state of which Melbourne is the capital, has said that Victoria would not permit entry to unvaccinated players.

Last week, Mr. Djokovic’s father, Srdjan Djokovic, said that his son was unlikely to participate in the tournament “under these blackmails and conditions.”

Novak Djokovic’s remark in October set off rounds of contradictory statements between Australian government ministers and tournament organizers about entry requirements for international visitors.

Alex Hawk, the immigration minister, said that unvaccinated players would not be able to enter Australia.

The Women’s Tennis Association told its players in a leaked email that unvaccinated players would be allowed to enter the country, though they would have to quarantine for two weeks upon arrival.

Prime Minister Scott Morrison said something similar: Unvaccinated players would be able to enter, but would need to comply with quarantine requirements for the state in which they arrived.