Top delegates from Russia and Ukraine wrapped up their ceasefire talks on Monday in Istanbul. Ukrainian President Volodymyr Zelenskyy said he expects the two sides will exchange more prisoners of war.

The second round of direct discussions, which finished in just over an hour, followed their negotiations in mid-May in the Turkish city. Ukrainian Defense Minister Rustem Umerov, who led his nation's delegation, confirmed that both sides handed over memorandums outlining their demands.

Zelenskyy updated his European counterparts in Vilnius, Lithuania, on Monday. He said, "If Russia turns the Istanbul meeting into an empty talk, there must be a new level of pressure, new sanctions, and not just from Europe."

He added that they should work on joint sanctions at the G7 level, including with the United States.

Turkish President Recep Tayyip Erdogan said it was a "great" meeting. He added Turkey will try to bring together the two leaders, along with US President Donald Trump. Erdogan said, " If they accept, I would like to come together with them in this meeting, and turn Istanbul into a peace center. "

The talks came after Ukraine launched massive drone attacks across Russia in an operation called "Spiderweb." Ukrainian officials said they targeted several air bases and hit 41 warplanes on Sunday.