Russia promised at peace talks on Tuesday to drastically scale down its military operations around Kyiv and the northern Ukrainian city of Chernihiv, while Ukraine proposed neutral status with international guarantees to protect it from attack.
Ukrainian negotiators said they had proposed a status under which their country would not join alliances or host bases of foreign troops, but would have its security guaranteed in terms similar to "Article 5", the collective defence clause of NATO.
They identified Israel and NATO members Canada, Poland and Turkey as countries that could help provide such guarantees.
The proposals would include a 15-year consultation period on the status of Russian-annexed Crimea, and could come into force only in the event of a complete ceasefire, the Ukrainian negotiators told reporters in Istanbul.
Russian Deputy Defence Minister Alexander Fomin said Russia had decided to scale down fighting near Kyiv and Chernihiv to create the conditions for dialogue.
Top Russian negotiator Vladimir Medinsky said he would examine the Ukrainian proposals and report on them to President Vladimir Putin.
The talks held in Istanbul on Tuesday were the first face-to-face meeting between the sides since March 10. Russia launched its invasion of Ukraine on February 24, and has failed to capture any major Ukrainian cities after meeting fierce resistance.
Ukraine's proposals were the most detailed and concrete that Kyiv has aired publicly.
"If we manage to consolidate these key provisions, and for us this is the most fundamental, then Ukraine will be in a position to actually fix its current status as a non-bloc and non-nuclear state in the form of permanent neutrality," said Ukrainian negotiator Oleksander Chaly.
"We will not host foreign military bases on our territory, as well as deploy military contingents on our territory, and we will not enter into military-political alliances," he said. Military exercises would take place with the consent of the guarantor countries.
The Ukrainian negotiators said there was enough material in their proposals to warrant a meeting between Ukrainian President Volodymyr Zelenskiy and Russian President Vladimir Putin.