Ukrainian President Volodymyr Zelensky addressed the Group of Seven leaders at their summit in Germany where they discussed the threat posed by the Russian invasion of his country to global stability.

The leaders met in a conference room at Schloss Elmau in Germany, a castle on a mountaintop.

Zelensky appeared on a small screen overlooking the group. The conflict was an ongoing topic throughout Prime Minister Justin Trudeau's meetings with world leaders at Schloss Elmau in Germany, as well as last week at the Commonwealth Heads of Government meeting in Rwanda.

Trudeau spoke to Zelensky on the first day of the G7 summit to inquire what he needed from the leaders.

According to Zelensky's Twitter account, the two discussed increasing defensive support for Ukraine.

The heads of the world's most advanced economies dedicated their first session to discussing the war and listening to Zelensky's calls for more help.

Before the meeting, Trudeau and the summit host Chancellor Olaf Scholz talked during a walk from the manor building.

Scholz told the media during a photo opportunity with Trudeau: "We are cautious about the aid provided to Ukraine as much as possible, but we also avoid a major conflict between Russia and NATO."

The night before in the Ukrainian capital Kyiv, Russian missile strikes targeted infrastructure after weeks of calm.

The city mayor said the missiles hit a kindergarten and a residential building, killing a man and injuring a woman and a child.

While the G7 leaders united in condemning Russia, they are also expected to meet with Narendra Modi, the Prime Minister of India, who has been invited to the summit. Trudeau will also meet Modi privately in a special meeting.

The UK announced on Sunday new sanctions on Russia that would ban the import of Russian gold, the country's largest non-oil export.

The UK government says the same applies to Canada, the United States, and Japan, which together, as a joint effort, would exclude Russia from official markets.

The idea is to "increase pressure on the Russian war machine," cutting funds from the country to finance the conflict.

Russia was on the verge of defaulting on its foreign debt for the first time since the 1917 Bolshevik revolution on Sunday, increasing the country's isolation from the global financial system.

Russia describes any default as artificial because it has the money to pay its debts but says sanctions have frozen its foreign currency reserves held abroad.