Trump-Putin summit: Zelenskyy to travel to DC on Monday to meet with President Trump

First lady Melania Trump penned a personal letter to Russian President Vladimir Putin raising concerns over children abducted during the Russia-Ukraine war, two White House officials tell ABC News.

President Donald Trump hand delivered the letter to Putin during their summit in Alaska, those officials said, but did not provide further details about the contents of the letter.

Ukrainian President Volodymyr Zelenskyy has said thousands of children have been kidnapped by Russia.

“We cannot reach an agreement with them on the return of the children,” Zelenskyy has stated.

The first lady was not on this trip, but the president often talks about how his wife reminds him of the brutality of Russia's attacks on Ukraine.

“I go home, I tell the first lady, ‘I spoke to Vladimir today, we had a wonderful conversation.’ And she says, ‘Oh really, another city was just hit,'” the president said weeks ago.

-ABC News’ Rachel Scott

President Donald Trump informed Ukrainian President Volodymyr Zelenskyy and European leaders that Russian President Vladimir Putin demanded at the Alaska summit that Ukraine withdraw from all of the Donetsk region in exchange for halting Russia’s offensive on two more southeastern regions, the Kherson and Zaporizhzhia, two sources confirmed to ABC News.

The sources familiar with the call said Putin had also agreed not to mount further attacks on Ukraine if it ceded the territory.

The remaining unoccupied third of the Donetsk region contains a belt of key defensive cities. Giving them up without significant security guarantees would leave Ukraine extremely vulnerable to re-invasion by Russia.

It is unclear for now what Trump is suggesting or what Putin would accept. On Friday, Trump suggested that the U.S. would be part of security guarantees, but has not indicated in what form.

Trump also told Zelenskyy and European leaders that Putin raised the issue of protecting the Russian language and Russian Orthodox Church in Ukraine, according to a source briefed on the call.

Those are long-standing demands from Putin, that suggest he has not changed his conditions for ending the war, which have included regime change.

-ABC News’ Yulia Drozd and Patrick Reevell

Russian President Vladimir Putin's top foreign policy aide, Yury Ushakov, who was present at the summit between Putin and President Donald Trump in Alaska, said a new meeting with Ukrainian President Volodymyr Zelenskyy was not discussed on Friday.

"For now the issue wasn't raised," Ushakov said, according to Russian state media.

When asked by Fox News' Sean Hannity whether a trilateral meeting did come up during the summit, Trump responded, "Yeah, it did."

But earlier in the interview, Trump said the meeting was being set up while also saying right after, "I didn't ask about it."

-ABC News' Patrick Reevell and Quinn Scanlan

In the first major statement from Ukraine’s European allies following the Trump-Putin summit in Alaska, European leaders reiterated Friday that Kyiv "must have ironclad security guarantees" and "welcomed President Trump's efforts to stop the killing in Ukraine."

"We are clear that Ukraine must have ironclad security guarantees to effectively defend its sovereignty and territorial integrity," the European leaders added. "It will be up to Ukraine to make decisions on its territory. International borders must not be changed by force."

"As President Trump said ‘there's no deal until there's a deal'. As envisioned by President Trump, the next step must now be further talks including President Zelenskyy, whom he will meet soon," the statement continued. "We are also ready to work with President Trump and President Zelenskyy towards a trilateral summit with European support."

-ABC News' Guy Davies