US and Ukrainian officials said they made substantial progress in two days of talks aimed to bring an end to Russia's invasion closer, but questions remained about key issues including the fate of territory that Kyiv continues to hold in the eastern Donetsk region.
Ukrainian President Volodymyr Zelenskyy said on December 15 that the talks were tough but useful, and his chief negotiator, Rustem Umerov, said that "real progress" was achieved in Berlin with White House special envoy Steve Witkoff and President Donald Trump's son in law, Jared Kushner, among other US delegates.
"These conversations are always not easy, I'll be honest with you. But it was a productive conversation, with a lot of details, really a lot," Zelenskyy said at a German-Ukrainian Business Forum that followed the US-Ukraine meeting.
At a news conference later with German Chancellor Friedrich Merz, Zelenskyy said the sides "have differences" on the matter of territory, saying that the issue is "not closed."
He said that Ukrainian negotiators would continue talks with the US delegation, and a US official said Trump would call in to a joint dinner.
"The territorial issue is painful. We know 100 percent what Russia wants - and it is key for me that the Americans heard me on this," Zelenskyy said.
"I believe that the Americans, as mediators, will be probing various ways how to resolve issues" including territory and funding for Ukraine's reconstruction.
The Americans "are working extremely constructively to help Ukraine find a way to a peace agreement that lasts," Umerov wrote on X.
"We hope we will reach an agreement that will bring us closer to peace by the end of the day," he wrote, but it was not clear whether he meant that literally.
The Reuters news agency cited unnamed US officials as telling reporters that there was consensus on a number of matters and that 90 percent of the issues between Russia and Ukraine have been resolved, but that there was more to discuss. Officials said Trump was happy with where things stand.
Merz was upbeat, saying that the biggest chance for a real peace process since the beginning of Russia's full-scale invasion in February 2022 has now emerged, and that the US has offered a major material contribution to security guarantees for Ukraine, a key issue.
With the US pushing for a peace deal, a key issue has been the fate of the part of Donetsk region in Ukraine's east that Kyiv's forces still hold despite years of efforts by Russia to capture the Donbas, which comprises the Donetsk and Luhansk regions, in its entirety.
Merz told reporters that only Ukraine can decide on territorial concessions, and a US official was cited as making a similar remark.
On another crucial matter, a US official told reporters the US is offering Kyiv strong "really, really strong" security guarantees in line with NATO's Article Five -- which calls an attack on one ally an attack on all -- and expressed confidence that Russia would accept the proposed measures.
"Those guarantees will not be on the table forever. Those guarantees are on the table right now if there's a conclusion that's reached in a good way," the official said.
20-Point Plan
The meeting on December 15 followed five hours of US-Ukraine talks a day earlier. After those talks, Witkoff said on X that "[a] lot of progress was made in "in-depth discussions regarding the 20-point plan for peace, economic agendas, and more." He did not provide details.
The 20-point plan emerged after Ukraine and its European backers scrambled to make counterproposals after the United States came out with a 28-point plan that echoed some of Moscow's positions and was widely seen as favorable to Russia.
"In my view, the most important thing is that the plan be as fair as possible -- first and foremost for Ukraine, because it was Russia that started this war," Zelenskyy said in a WhatsApp chat with reporters before the talks on December 14. "And above all, it must be workable."
SEE ALSO: The Donbas And Beyond: The Territorial Barriers To Peace In UkraineCould The EU Use Frozen Russian Assets To Help Ukraine?
Meanwhile, European Union leaders are set to decide at a summit on December 18 whether the EU can use tens of billions in frozen Russian assets to back a large loan to Ukraine, whose economy is struggling nearly four years into the all-out war.
"If we do not succeed in this, then the European Union's ability to act will be severely damaged for years, if not longer, and we will show the world that we are incapable of standing together and acting at such a crucial moment in our history," Merz said.
Another barrier to peace is the fact that Russian President Vladimir Putin, who launched the invasion in an effort to subjugate Ukraine, has given few indications he is prepared to make meaningful concessions.
Zelenskyy said on December 14 that Ukraine is ready to drop its desire to join NATO, at least for now, but that ironclad Western security guarantees are needed to ensure Russia does not attack again at some point after a peace deal is reached.
"From the very beginning, Ukraine's desire was to join NATO -- these are real security guarantees," Zelenskyy said in response to a reporter's question in a WhatsApp chat. "Some partners from the US and Europe did not support this direction," he said.
"Thus, today, bilateral security guarantees between Ukraine and the US, Article 5-like guarantees for us from the US, and security guarantees from European colleagues, as well as other countries -- Canada, Japan -- are an opportunity to prevent another Russian invasion," he wrote.
That is "already a compromise from our part," he said, adding that any such guarantees should be legally binding.
Putin's spokesman Dmitry Peskov said on December 15 that a bar against Ukraine joining NATO is a "cornerstone" of any peace deal in the Kremlin's eyes, and that Russia expects to hear from US officials following the talks in Berlin, which Moscow was not involved in.
SEE ALSO: Here's Why Russia's Vladimir Putin Is Fixated On Ukraine's DonbasIn the chat before the talks on December 14, Zelenskyy pushed back against proposals that would require Kyiv to cede, even de facto, the portion of the Donetsk region that its forces still hold. And if Ukraine does have to pull back from the front lines in the Donbas, he suggested that Russian forces would have to do so as well.
Zelenskyy said that the US is proposing creating a "free economic zone" in the part of the Donetsk region that Kyiv still controls, with Ukrainian forces withdrawing and Russian forces forbidden to enter.
Putin adviser Yury Ushakov, however, repeated the Kremlin's baseless claim that Donetsk and Luhansk are Russian territory and said Moscow would deploy National Guard troops and police in any demilitarized zone there.
Zelenskyy said last week that any potential territorial concession should be put to a vote by the Ukrainian populace. And on December 14, he said that if "Ukrainian forces withdraw 5–10 kilometers, for example, why would Russian forces not also withdraw the same distance deeper into the occupied territories?"
"So this is a question that remains unanswered for now. But it is extremely sensitive and very heated," he said.
Trump has been seeking to broker and end to the war since he took office for a second time in January of this year, but progress has been slow and Putin has said Russia will achieve its goals by force if it cannot do so through diplomacy.
White House spokeswoman Karoline Leavitt said last week that Trump is “extremely frustrated with both sides of this war.”
Russian forces have continued to bombard cities across Ukraine and try to press forward on the front lines in the east and south amid the latest flurry of diplomatic meetings.
Ukraine main security service, the SBU, said on December 15 that Ukrainian forces struck and caused critical damage to a Russian submarine in the Black Sea port of Novorossiisk, where part of Russia's fleet is based.