Ukrainian President Volodymyr Zelenskyy has said that protecting Ukraine’s territorial integrity remains the “biggest challenge” in ongoing negotiations over a US plan to end the war, following discussions in Paris with European and US officials.

Speaking alongside French President Emmanuel Macron at a joint news conference on Monday, Zelenskyy said Ukraine’s priorities include security guarantees, sovereignty and preventing concessions that would legitimise Moscow’s occupation of Ukrainian land.

“Our biggest challenge is the territorial issue,” he said, urging partners to avoid any outcome that “rewards the war it [Russia] started”.

The comments came as officials from France, Germany, Italy, Poland and the United Kingdom joined discussions in Paris, holding calls with US special envoy Steve Witkoff as part of an intensifying diplomatic push to end the war, which Russia launched with its full-scale invasion in February 2022.

Zelenskyy said the meeting also reviewed the substance of talks held a day earlier between Ukrainian and American officials in the United States, adding that more meetings are being prepared across Europe.

Macron reiterated that “Ukraine must be the one to decide its own territorial boundaries”, while signalling that further discussions are planned between Washington and European allies on potential security guarantees for Ukraine should a deal to end the war emerge.

Italian Prime Minister Giorgia Meloni also emphasised the need for unity between Europe and the US on a pathway towards peace. In a statement, she praised Zelenskyy’s “consistently constructive approach” and said she hoped Russia would “offer its own concrete contribution” to future talks.

Territorial question deepens diplomatic tensions

The territorial issue is shaping up to be the most sensitive point in negotiations, as Witkoff and US President Donald Trump’s son-in-law, Jared Kushner, prepare to meet Russian President Vladimir Putin on Tuesday.

Zelenskyy has said he hopes to speak with Trump after those talks. But Ukrainian officials have already told the US that Kyiv will not accept any settlement requiring it to cede territory.

“We told the American side that it is unacceptable for Russia to continue its occupation of our territory and then demand that we grant it legitimacy,” Zelenskyy’s adviser, Rustem Umerov, told Al Jazeera Arabic. “Giving up our territory means that international law no longer exists and that any party can use force to abolish the sovereignty of another party.”

Umerov said security guarantees remain a delicate part of discussions, because “we are seeking security for both Europe and Ukraine”. He added that negotiations will be “extremely difficult” if Russia genuinely engages, arguing that Moscow still believes “continuing the war is less costly than ending it”.

Reporting from Brussels, Al Jazeera’s Hashem Ahelbarra said that European Union leaders are insisting that no major concessions be made to Russia, and that “instead of handing over territory, there need to be land swaps that can only be decided by the Ukrainian people”.

It comes after a draft US plan was leaked to the press in mid-November, prompting criticism in Ukraine and among its European allies, who said the document heavily favoured Moscow.

The plan had proposed to limit Ukraine’s army strength to 600,000 men, with no mention of any cap on Russia. It also barred Kyiv from ever joining NATO, and included plans for Moscow to keep captured Ukrainian territories.

Russian strikes hit Dnipro

As diplomatic efforts accelerate, Ukraine suffered another deadly attack earlier on Monday. Local officials said at least four people were killed in a Russian missile strike on the central city of Dnipro.

Interfax reported that injuries have risen to 43, citing Vladyslav Haivanenko, the acting head of the Dnipropetrovsk Regional Military Administration. He said 10 people were in serious condition. The strike damaged an administrative building, several businesses, four educational institutions, multiple high-rise buildings, two service stations and more than 50 vehicles.

Dnipro, located about 100km (62 miles) from the front line and home to nearly one million people before the war, is frequently targeted by Russian bombardments.

Russia’s Ministry of Defence said its forces had “liberated” the settlement of Klynove in Ukraine’s Donetsk region, claiming it had advanced deep into Ukrainian positions. However, the Ukrainian army has refuted these claims.

Moscow said Ukraine lost about 1,415 troops across the front over the past 24 hours. Kyiv, meanwhile, reported eliminating 1,060 Russian troops, one tank, six armoured vehicles, 14 artillery systems, 239 drones and 71 vehicles in the same period.

Al Jazeera could not independently verify either side’s battlefield claims.