For full coverage of the crisis in Ukraine, visit .

Pope Francis welcomed the departure from Ukrainian Black Sea ports of the first ships carrying grain previously blockaded by Russia, saying the breakthrough could be a model for dialog to bring an end to the war in Ukraine, \

Latest Developments in Ukraine: August 7

The first ship, the Razoni, set off on Aug. 1 with seven more following through Sunday, thanks to a grain and fertilizer export deal between Moscow and Kyiv brokered by Turkey and the United Nations last month.

Latest Developments in Ukraine: August 7

It came after U.N. warnings of possible outbreaks of famine in some areas of the world due to a halt in grain shipments from Ukraine that had squeezed supplies and sent prices soaring.

Latest Developments in Ukraine: August 7

"This step shows that it is possible to conduct dialog to reach concrete results, which help everyone," Pope Francis said at his weekly address to pilgrims and tourists in St. Peter's Square. “This event presents itself as a sign of hope and my own heartfelt wish is that following this path, it will be possible to bring an end to the fighting and reach a just and lasting peace.”

Ukraine is investigating almost 26,000 suspected war crime cases committed since Russia's Feb. 24 invasion and has charged 135 people, its chief war crimes prosecutor .

Of those charged, around 15 are in Ukrainian custody and the remaining 120 remain at large, Yuriy Bilousov, head of the war crimes department of the Prosecutor General's office, said in an interview in the capital Kyiv.

Thirteen cases have been submitted to courts and seven verdicts have been issued, he said.

In May, a 21-year-old captured Russian soldier became the first person to be convicted in a war crimes trial in Ukraine since Russia invaded on Feb. 24. He was sentenced to life in prison for killing an unarmed civilian.

"Sometimes we've been asked why we prosecute such … low-ranked officers. It's just because they are physically here. ... If generals were here physically and we were able to capture (them), we would definitely prosecute generals," Bilousov told Reuters.

Former Russian deputy prime minister Arkady Dvorkovich was re-elected for a second term as president of the (FIDE), defeating a Ukrainian who had criticized him over Moscow's military actions, Reuters reported.

Former U.S. diplomat Bill Richardson said he was "optimistic" about efforts to negotiate a "two for two" prisoner swap with Russia that would free U.S. basketball star Brittney Griner and another American, Agence France-Presse reported.

Richardson, a former ambassador to the U.N., has negotiated the release of several Americans held in other countries. Reports last month said he was expected to travel to Russia for talks over Griner, who on Thursday was sentenced to nine years in prison on a drug charge.

While insisting Sunday that he is only a "catalyst" in any negotiations, Richardson's mention of a "two-for-two" swap, including Griner suggested inside knowledge.

"My view is, I'm optimistic," he told ABC's "This Week." "I think she's going to be freed, I think she has the right strategy of contrition, there's going to be a prisoner swap -- though I think it will be two for two, involving Paul Whelan."

Whelan is a former U.S. Marine who was convicted of espionage in June 2020 and sentenced to 16 years in prison. He has insisted on his innocence.

His case and Griner's have been enmeshed in the deep U.S.-Russia tensions since Russian troops invaded Ukraine in February, AFP reported.

Ukrainian President Volodymyr Zelenskyy met with American actress Jessica Chastain in Kyiv, The Associated Press reported. During the meeting, Chastain described Ukrainians as "incredibly brave and very strong."

"For us, such visits of famous people are extremely valuable," the Ukrainian leader wrote in his Telegram channel. "Thanks to this, the world will hear, know, and understand the truth about what is happening in our country even more."

Ukrainian President Volodymyr Zelenskyy said that Russia will lose any chance of negotiating with Ukraine should it conduct referendums in the occupied territories, The Associated Press reported.

"If the occupiers follow the path of these pseudo-referendums, they will close any possibility of negotiations with Ukraine and the free world for themselves," he said in his nightly address.