President Vladimir V. Putin of Russia again blamed Western countries for the war in Ukraine in a wide-ranging speech via video link on Wednesday to the five-nation BRICS summit, keeping up his attempts to rally the member countries to Moscow’s side.

Addressing fellow leaders of the group, which includes Brazil, Russia, India, China and South Africa, on the second day of the meeting, Mr. Putin said Russia would assume chairmanship of the group next year and host a summit in the city of Kazan in October 2024.

Moscow launched its unprovoked full-scale invasion of Ukraine almost 18 months ago, but the Kremlin has sought to portray the decision as a defensive move against a hostile Ukrainian government, and antagonism from the United States, Europe and NATO.

“Our actions in Ukraine are guided by only one thing — to put an end to the war that was unleashed by the West,” Mr. Putin added, according to an English translation of the live video stream of his address provided by the South African Broadcasting Corporation, in a familiar refrain.

Mr. Putin is the only leader of a BRICS nation not to attend the summit in Johannesburg in person this week because he is wanted for war crimes under a warrant issued by the International Criminal Court. South Africa, which is a party to the treaty that created the court and would have been obliged to arrest him if he had traveled there, had asked him to stay away.

The summit has focused on whether to expand the club and how to be a counterweight to Western powers. The war in Ukraine, the prospect of a major BRICS expansion and heightened tensions between China and the United States have drawn unusual attention to the meeting.

BRICS members have seen it as the kernel of a diplomatic and economic bloc to counterbalance Western-dominated alliances like the Group of 7. Dozens of other countries have applied for entry, and Saudi Arabia, Indonesia, Egypt and Argentina are among those considered to be at the top of the list.