Canadian Prime Minister Justin Trudeau visited Ukraine on Sunday and toured devastated areas in and around Kyiv with Ukrainian President Volodymyr Zelenskyy.

During a joint news conference, Trudeau pledged Canada's continuing support for Ukraine and condemned Russian President Vladimir Putin for atrocities he alleged Russian forces are responsible for in Ukraine.

"It is clear that Vladimir Putin is responsible for heinous war crimes," Trudeau said. "We will continue to do the work of being there for you with whatever we can, whatever you need."

Trudeau announced that Canada is sending additional military support to Ukraine, including drone cameras, satellite imagery, small arms and ammunition.

The prime minister also said Canada will impose new sanctions on 40 Russian individuals he alleged are complicit in Putin's war.

"And we're bringing forward new sanctions on 40 Russian individuals and five entities, oligarchs and close associates of the regime in the defense sector, all of them complicit in Putin's war," Trudeau said.

Trudeau also announced that all trade tariffs on Ukrainian imports to Canada will be lifted for the next year and that Canada is donating CA$25 million, or about US$19.3 million, to the U.N. World Food Program, which is providing emergency food assistance to people in Ukraine.

Trudeau said that he and Larissa Galadza, Canada's ambassador to Ukraine, raised the Canadian flag at the country's embassy in Kyiv on Sunday to signal its reopening. He called the move an "important symbol not just of Canada's steadfast friendship with Ukraine, but of the incredible resilience and heroism of the Ukrainian people, who ensured that this city did not fall."

-ABC News' Christine Theodorou

Pope Francis on Sunday prayed for peace in Ukraine, entrusting to the Virgin Mary the ''sufferings and tears of the Ukrainian people."

''In front of the war's madness, let us please continue to pray the rosary for peace every day," the pope told thousands of people gathered in the Vatican's St. Peter's Square for his weekly address and blessing.

For several Sundays in a row the pope has led prayers for peace in Ukraine and has condemned the Russian invasion of the country, calling the act of war "senseless" during an Easter Sunday Mass last month.

The pontiff also prayed for the victims of an apparent gas explosion on Friday at the Hotel Saratoga in Havana, Cuba. At least 26 people were killed in the blast at the popular hotel and around 70 people were injured.

U2's frontman Bono and lead-guitarist The Edge surprised fans in Kyiv on Sunday by performing an impromptu concert in the Ukrainian capital's central metro station.

The two Irish rockers delivered a nearly hour-long set at the Khreshchatyk Metro Station, Kyiv's busiest metro station, as several dozen fans watched.

"The people of Ukraine are not just fighting for your own freedom, you're fighting for all of us who love freedom," Bono told the crowd between songs.

The musicians were joined on one of the station's platforms by Taras Topolia, frontman of Ukrainian pop rock band Antytila. Topolia presented Bono with a piece of shrapnel he said was the remains of a missile that struck near the base in Kyiv where he is currently serving in the Ukrainian Army.

The United States and its G-7 allies announced a new round of sanctions on Sunday against Russia, including some aimed at crippling three of Russia's largest state-controlled television stations.

The new sanctions were announced after leaders from the G-7 group held a virtual summit with Ukrainian President Volodymyr Zelenskyy.

"Putin has failed in his initial military objective to dominate Ukraine -- but he has succeeded in making Russia a global pariah. Today, the United States, the European Union and G7 committed to ratchet up these costs by collectively taking further measures, consistent with each partner’s respective legal authorities and processes,” reads a fact sheet of the new measures released by the White House.

Sanctions will be imposed against Russia's Channel One, Russia-1 and the NTV Broadcasting Company, including cutting off the outlets' access to technology like video cameras, microphones, lighting equipment and software services, according to the fact sheet. Advertising dollars derived from the United States will also be prohibited from funding the companies.

“Russia can try to produce these components domestically but the idea here is to make that commercially difficult, unprofitable, put more of the burden on the Russian state. We’re not going to be in the business of helping them broadcast the lies and deceit that you hear from Putin every day,” a senior Biden administration official said.

The entire G-7 also announced it is committed to phasing out or banning the import of Russian oil.

Additionally, the new sanctions prohibit anyone from the United States from providing accounting, trust, corporate formation and management consulting services to members of Russian Federation.

The United States is also imposing about 2,600 visa restrictions for Russian and Belarussian officials, and creating a new visa restriction policy for Russian Federation military officials and “Russia-backed” or “Russia-installed” officials believed to be involved in human rights abuses, violations of international humanitarian law or corruption in Ukraine.

New restrictions are to be imposed on wood products, industrial engines, motors, and bulldozers, according to Biden administration officials.

The administration is also sanctioning Promtekhnologiya LLC, a Russian company that manufactures rifles and weapons Russian forces have used in Ukraine.

In addition to the new sanctions, the U.S. Nuclear Regulatory Commission is suspending licenses for exports of special nuclear material, byproduct material and deuterium, or heavy hydrogen, to Russia.

ABC News' Armando Garcia

Jalina Porter, the State Department's deputy spokesperson, is responding to the Russian attack at a Ukraine train station that killed at least 50, saying, "We can no longer be surprised by the Kremlin's repugnant disregard for human life."

Five children were among those killed when Russian rockets struck the station in Kramatorsk in Donetsk Oblast on Friday morning, according to Ukraine's state-owned railway company. At least 100 people were injured, according to Donetsk Oblast Gov. Pavlo Kyrylenko.

Russia has denied involvement in the attack, which occurred as "thousands" of civilians fleeing the Russian invasion were at the train station waiting to be taken to "safer regions of Ukraine," according to Kyrylenko.

"Civilians are killed when they stay in their homes, and they're killed when they try to leave," Porter said. "Actions like these demonstrate why Russia did not belong on the U.N. Human Rights Council, and they also reinforce the U.S. assessment that members of Russian forces are committing war crimes in Ukraine."

Porter declined to say if the department considers the train station attack a war crime, saying, "Assessing individual criminal liability in specific cases is the responsibility of courts, as well as other investigatory bodies. But as the secretary, Secretary [of State Antony] Blinken, has said, 'Those responsible for war crimes and other atrocities committed in Ukraine will be held to account.'"

-ABC News' Conor Finnegan