NEW DELHI — As expected, Russia and India, longtime allies, signed a raft of agreements at their leaders’ annual summit meeting on Thursday, expanding their usual set of projects to an ambitious agenda that includes the joint manufacture of military helicopters and production of nuclear reactors.

But the most intriguing event of the day occurred across town in a private dining room at a luxury hotel, where Sergei Aksyonov — the barrel-chested prime minister of Crimea, the Ukrainian territory annexed by Russia — signed a memorandum of understanding with a group of Indian businessmen who call themselves the Indo-Crimean Partnership.

The symbolic show of support put India in the middle of one of the most bitter disputes between Moscow and the West.

Mr. Aksyonov organized a paramilitary force on the Crimean Peninsula early this year as pro-Western protests rose in Kiev, the Ukrainian capital, and he was one of the first people to be singled out by the United States for sanctions. He traveled to India on a plane with Russian officials attending the meeting, and was flanked by Russian diplomats, whom he credited with arranging the event. Interfax, the Russian news agency, said it was Mr. Aksyonov’s “first international visit.”