President Volodymyr Zelensky of Ukraine on Thursday appointed Valery Zaluzhny as his new ambassador to Britain, just a month after he removed him from his post as the country’s top general amid tensions between the military and civilian leadership.

“Gen. Valery Zaluzhny told me that this is the direction he would like to take — diplomacy,” Mr. Zelensky said in a video statement, adding that Ukraine’s “alliance with Britain should only get stronger” with this appointment.

Thursday’s announcement ended weeks of speculation about the fate of General Zaluzhny, whose relationship with Mr. Zelensky had become strained. His dismissal from the army command was seen as the result of Mr. Zelensky’s frustration at the failure of Ukraine’s counteroffensive last summer, but also possibly the product of his fears that the general, a very popular figure in Ukraine, might become a political opponent in the future.

In Britain, General Zaluzhny will occupy an influential position that has been vacant since the summer, but one distant from Ukraine’s military and political decision-making. One of his missions will be to shore up support for the Ukrainian war effort among European countries as sustained American military aid is in doubt.

Mr. Zelensky made the announcement on a day when the British defense secretary, Grant Shapps, visited Kyiv. Mr. Shapps said that his country would supply more than 10,000 drones to the Ukrainian Army as part of an existing military aid package that received additional funding, for a total of about $415 million.

In Ukraine, General Zaluzhny has been nicknamed the Iron General for his decisive leadership of the country’s army at its most challenging times, including the defense of the capital, Kyiv, in the first weeks of the war.