MOSCOW—Vladimir Putin will most likely deliver a speech at the 70th anniversary opening session of the United Nations General Assembly in New York in September, his spokesman said—an appearance that would mark the Russian president’s first U.N. General Assembly speech in a decade.

“It is highly likely that such a trip and speech will take place,” Kremlin Spokesman Dmitry Peskov said, according to the Russian state news agency Tass. However, he added that a final decision wouldn’t be made until this summer.

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