US negotiators on Monday held talks with representatives from Russia to push forward a proposed partial ceasefire in the three-year war in Ukraine.
Moscow and Kyiv have struggled to reach the limited, 30-day ceasefire, which was agreed to in principle last week.
Both sides have continued to attack each other with drones and missiles despite the agreement.
On Monday evening, Ukrainian officials said children were among the casualties after a Russian missile attack injured 88 people in the Ukraine city of Sumy.
“Every day like this, all the nights with Russian missiles and drones against our country, every day of the war means losses, pain and destruction that Ukraine never wanted,” Ukrainian President Volodymyr Zelenskyy said in his evening address.
One major sticking point in negotiations is what targets are off-limits to strike.
US negotiators originally proposed a ceasefire on both "energy and infrastructure" however the Kremlin has declared the agreement should more narrowly cover simply "energy infrastructure."
Zelenskyy has declared he would also like to see infrastructure such as railways and ports protected.
After the talks on Monday, US President Donald Trump said that territorial lines and potential US ownership of Zaporizhzhia nuclear power plant in southern Ukraine were part of discussions.
“Some people are saying the United States should own the power plant — work it that way because we have the expertise” to get the plant operating, Trump said. “Something like that would be fine with me.”
The nuclear power plant — Europe's largest — has been under Russian control since the early days of the invasion. Zelenskyy has publicly rejected the concept of US firms owning Ukrainian power plants.
The US is expected to move between Russia and Ukraine to finalise details of the ceasefire and also negotiate measures to ensure a separate ceasefire in the Black Sea.
“We’re not far away from that,” US Special Envoy Steve Witkoff said of a permanent ceasefire during a podcast episode with Tucker Carlson over the weekend.
He also claimed that within the four regions Moscow has claimed as under its control — Donetsk, Kherson, Luhansk, and Zaporizhzhia — the "overwhelming majority of people have indicated they want to be under Russian rule", despite referendums held in these provinces being slammed as illegitimate by the west.
Grigory Karasin, head of the foreign affairs committee in the Russian parliament’s upper house and a participant in Monday’s talks, told the Interfax news agency the negotiations were going on in a “creative way" and that the US and Russian delegations “understand each other’s views.”
Zelenskyy on Sunday evening said that "since March 11, a proposal for an unconditional ceasefire has been on the table, and these attacks could have already stopped. But it is Russia that continues all this.”
On Monday, the Ukrainian leader said US and Ukraine representatives were set to meet again, although did not specify when.
