Washington and Moscow's top diplomats agreed at high-stakes talks on Friday to keep working to ease tensions over Ukraine, with the United States promising a written response to Russian security demands next week.
As fears grow that Russian could invade its pro-Western neighbour, US Secretary of State Antony Blinken and Russian Foreign Minister Sergei Lavrov sat down for 90 minutes of hastily-arranged talks in Geneva.
Russia has massed tens of thousands of troops on the Ukrainian border, denying it plans to invade but demanding security guarantees, including a permanent ban on the country joining Nato.
Blinken said after the talks that Washington will share written ideas with Russia next week, voicing hope for more diplomacy.
"We didn't expect any major breakthroughs to happen today, but I believe we are now on a clear path in terms of understanding each other's concerns and each other's positions," Blinken told reporters.
"We anticipate that we will be able to share with Russia our concerns and ideas in more detail in writing next week and we agreed to further discussions after that," he added.
"We ended up with an agreement that we will receive written responses to all our proposals next week," Lavrov said in a separate press conference.
"Antony Blinken agreed that we need to have a reasonable dialogue, and I hope emotions will decrease," Lavrov said.
"I cannot say whether or not we are on the right track. We will know when we get an answer," Lavrov said.
He added that another meeting could be held between the two, but that it was "premature" to start talking about a summit between Presidents Joe Biden and Vladimir Putin.
Biden bluntly assessed on Wednesday that Putin is likely to "move in" on Ukraine and warned of a "disaster for Russia".
The United States and its allies have warned of severe economic sanctions for an invasion.
Russia, which already fuels a deadly insurgency in eastern Ukraine that has killed more than 13,000 people since 2014, has demanded guarantees that Nato never admit the former Soviet republic or expand otherwise in Moscow's old sphere.
The United States has declared the idea a "non-starter" and accused Russia of undermining Europe's post-Cold War order by bullying another country into submission.
Russia on Friday reiterated demands for the "withdrawal of foreign forces, hardware and arms" from countries that were not Nato members before 1997, this time singling out Bulgaria and Romania, two former Warsaw Pact countries that joined Nato in 2004.
Romania's foreign ministry quickly hit back, calling saying the demand "is unacceptable and cannot be part of a negotiation."
Blinken headed to Geneva after a solidarity trip to Kyiv and talks with Britain, France and Germany in Berlin.
Even while rejecting the core Russian demands, the Biden administration has said it is willing to speak to Moscow about its security concerns.
One proposal by the United States is to revive restrictions on missiles in Europe that had been set by the Intermediate-Range Nuclear Forces Treaty, a Cold War deal trashed by former president Donald Trump's administration as it accused Moscow of violations.
The Biden administration has also offered more transparency on military exercises.
Russia has not rejected the proposals but says that its core concern is Ukraine and on Thursday announced massive naval drills in the Atlantic, Pacific, Arctic and Mediterranean as a show of force.
The United States has warned that the clock is ticking, putting forward intelligence alleging that an invasion could come shortly and be preceded by a "false-flag" operation as Russia tries to trigger a pretext against Ukraine.
Lawmakers in Russia's parliament have presented a bill that would ask Putin to recognise the independence of two pro-Moscow separatist territories in Ukraine, Donetsk and Lugansk.
Lower house speaker Vyacheslav Volodin said on Friday that such a move - sure to enrage Ukraine and prompt Western condemnation - would be "a solution to provide for the security of our citizens and countrymen" in the two regions.
Ukraine's military intelligence service on Friday accused Russia of sending fresh arms and equipment to the rebels since the start of this month, including tanks, artillery and ammunition. (AFP)