Russia has responded to the United States' formal rejection of its core demands to resolve the Ukraine crisis, saying it did not leave much room for optimism but dialogue was still possible.
Kremlin spokesman Dmitry Peskov said Moscow would not rush to draw conclusions after Washington on Wednesday formally responded to Russian proposals for a redrawing of post-Cold War security arrangements in Europe.
Describing tensions on the continent as reminiscent of the Cold War, Mr Peskov said it would take time for Moscow to review the response from Washington.
But he said the US and NATO rejection of Russia's main demands left "little ground for optimism".
"We cannot say that our thoughts have been taken into account or that a willingness has been shown to take our concerns into account," Mr Peskov said.
"But we won't rush with our assessments."
At the same time, he added that "there always are prospects for continuing a dialogue, it's in the interests of both us and the Americans".
The nuanced Kremlin reaction made clear that Russia was not rejecting the US and NATO responses out of hand or closing the door to diplomacy.
Moscow has massed around 100,000 troops near the border with Ukraine, prompting fears of a Russian invasion, which the Kremlin has repeatedly denied.
Russian Foreign Minister Sergey Lavrov noted that the US response contained some elements that could lead to "the start of a serious talk on secondary issues" but emphasised that "the document contains no positive response on the main issue".
Mr Lavrov told reporters that top officials will now submit their proposals to Russian President Vladimir Putin, who has the American response, and Mr Peskov said the Russian reaction would come soon.
The evasive official comments reflect the fact that it is Mr Putin who single-handedly determines Russia's next moves.
The Russian leader has warned that he could order unspecified "military-technical measures" if the West refuses to heed the Russian security demands.
Mr Peskov added that Mr Putin and US President Joe Biden would decide whether they needed to have another conversation, following two calls last month.
'There is no change, there will be no change'
The demands Russia outlined in December included that NATO halt any further enlargement, bar Ukraine from ever joining the grouping and pull back forces and weaponry from eastern European countries that joined it after the Cold War ended.
US Secretary of State Antony Blinken said after the written response had been handed over that Washington remained committed to upholding NATO's "open-door" policy and NATO said it would not compromise its core principles.
"There is no change, there will be no change," Mr Blinken said, repeating the warning that any Russian incursion into Ukraine would be met with massive consequences and severe economic costs.
The US and NATO have both said, however, they are willing to talk to Russia about arms control, confidence-building measures and limits on the size and scope of military exercises in order to reduce tensions.
Ukrainian Foreign Minister Dmytro Kuleba said he believed Russia was likely to remain on a diplomatic track with Kyiv and the West for at least two weeks.
Speaking after Russia held security talks in Paris on Wednesday with diplomats from Ukraine, France and Germany, Mr Kuleba told a news briefing in Copenhagen: "Nothing has changed, this is the bad news."
"The good news is that advisers agreed to meet in Berlin in two weeks, which means that Russia for the next two weeks is likely to remain on the diplomatic track," he said.
The so-called "Normandy" talks in Paris were seen as a step towards defusing broader tensions in a separatist conflict in eastern Ukraine.
While the diplomacy sputters on, so, too, do manoeuvres on both sides that have escalated tensions.
Russia has launched a series of military drills in the region while NATO said it was bolstering its deterrence in the Baltic Sea region, and the US ordered 8,500 troops on higher alert for potential deployment to Europe.
Ukrainian soldier opens fire on comrades
Against the background of rising tensions and diplomatic manoeuvring, a member of Ukraine's National Guard on Thursday opened fire on his fellow soldiers.
Five people were killed and five more were injured, Ukraine's Interior Ministry said. The serviceman was detained by police but his motives remain unclear.
The incident occurred in the city of Dnipro, 500 kilometres south-east of Kyiv. The soldier, identified by the authorities as Artemiy Ryabchuk, 20, was on guard duty at a military factory and opened fire on his colleagues, fleeing the scene immediately after.
The dead included four soldiers and one civilian.
President Volodymyr Zelensky demanded the authorities thoroughly investigate and analyse the incident.
"I expect law enforcement to fully inform the public about all the circumstances of the crime. Motives of the killer, how [the shooting] became possible — everything should be analysed as thoroughly as possible," he said in an online statement
ABC/wires
