Amid the Russia-Ukraine crisis, which is the largest military conflict in Europe since World War II, Pope Francis made an address to the world from the Vatican on Sunday where he pleaded for peace to prevail.

Those in attendance held up Ukrainian flags to show support for the people most affected by the violence.

“Rivers of blood and tears are flowing in Ukraine. This is not a military operation, but a war, which sows death, destruction, and misery. The number of victims is increasing, as are the people fleeing, especially mothers and children,” the Pope said.

Pope Francis seemingly referenced claims by Russian President Vladimir Putin that the invasion of Ukraine by the Russian military is not a war, but a “special military operation,” which was officially launched last month. At that time, the Pope went to the Russian embassy to express his concerns about the conflict.

The war has now lasted almost two weeks and around 1.5 million Ukrainians have fled their homes as a result, Filippo Grandi, the U.N.'s high commissioner for refugees, told CBS News. Russia’s invasion of Ukraine has received worldwide condemnation and the Ukrainian people have received global sympathy, with thousands of protests taking place around the world.

“In that martyred country the need for humanitarian assistance is growing by the hour. I make a heartfelt appeal for humanitarian corridors to be genuinely secured, and for aid to be guaranteed, and facilitated access to the besieged areas to provide vital relief to our brothers and sisters oppressed by bombs and fear,” the Pope added.

So far negotiations have not proven to be successful, with Russia increasing its attacks on civilian-populated areas, cities, and on a nuclear power plant in Ukraine, the largest in Europe.

The Pope also announced during his speech that two cardinals had been sent to the region to help those in need.

“I would like to thank all those who are taking in refugees, and above all, I import that the armed attacks cease and that negotiation prevails, that common sense prevails, and that we return to respecting international law,” he said.