Algerian President Abdelmadjid Tebboune flew back to Germany on Sunday for treatment in hospital for complications in his foot resulting from a coronavirus infection.
Mr Tebboune, 75, had returned home two weeks ago from Germany after two months of treatment for Covid-19.
The treatment "was not medically urgent" and should have taken place during Mr Tebboune's last stay in Germany, the presidency said.
Mr Tebboune postponed the treatment at the time because of some obligations that prompted him to return home on December 29, it said.
Late in December, Mr Tebboune signed this year's budget into law, along with a decree paving the way for an amendment to the constitution.
Speaking to state television near the capital, Algiers, Mr Tebboune said he might undergo surgery on his foot.
"There may be a minor surgery. My return to Germany was previously planned. The period of my absence from the country will be short, God willing," he said. "I will be following state issues with officials on a daily basis."
Elected in December 2019 to succeed Abdelaziz Bouteflika, who resigned after mass protests, Mr Tebboune has promised to carry out political and economic reforms.