Russian President Vladimir Putin was a target of mockery by leaders of the Group of Seven, as they sat around a table Sunday, commencing their three-day summit in Germany's Bavarian Alps.

Before leaders launched into a discussion regarding the Russian president’s invasion of Ukraine, and their strategies towards immobilizing Russian assets, British Prime Minister Boris Johnson asked if they should remove their jackets -- or if they should “disrobe even further.”

“We all need to show that we’re tougher than Putin,” he joked, prompting some laughter from his colleagues.

Canada’s Prime Minister Justin Trudeau joined in, saying, “We’re going to get the bare-chested horseback riding display.”

Putin has been pictured shirtless, riding a brown horse, wearing army trousers, a gold chain and wrap-around sunglasses in images released by Russian state media.

Boris Johnson then gestured to the cameras stationed behind the table.

“We’ll show them our pecs,” he said.

The meeting was not all humour, though.

Early Sunday morning, Russian missiles hit the Ukrainian capital city of Kyiv, striking two residential buildings and killing at least one person.

The attack was the latest act of destruction in an invasion that has killed thousands and forced millions from their homes.

The world's response to the Russian invasion is set to be a key topic at the G7 summit, and U.S. President Joe Biden has condemned Russia's actions as "more of their barbarism."

Meanwhile, Johnson urged leaders not to give in to "fatigue".

Leaders of Britain, Canada, Japan, France and the United States also discussed commodity bans and other ways to reaffirm their condemnation of Russia.

With files from Reuters