BRUSSELS—The interceptions of a U.S. Air Force plane and a Navy destroyer by Russian warplanes last week were unsafe and highlight the need for discussion between Russia and the Western allies, the head of North Atlantic Treaty Organization said Tuesday.

Jens Stoltenberg, the NATO secretary-general, said the alliance would discuss Russia’s risky military maneuvers and related issues when allied ambassadors meet with Russian officials Wednesday.

The meeting of the NATO-Russia Council in Brussels will be the first since June 2014, when the alliance cut off practical cooperation with Moscow following the annexation of Ukraine’s Crimean peninsula.

“The incidents we have seen in the Baltic Sea over the last week with the unprofessional and unsafe behavior of Russian planes close to an American ship and an American plane underline the importance of open military lines of communication, predictability and risk reduction,” Mr. Stoltenberg said in Luxembourg, where European Union defense ministers were meeting.

According to the U.S. account, Russian warplanes and a military helicopter repeatedly buzzed the USS Donald Cook, as it carried out operations in the Baltic Sea on April 11 and 12.