Russia's chief negotiator Vladimir Medinsky confirmed a TASS news report that "several long conversations" had been held by phone but he gave no details.Â
Earlier this week the Kremlin said Russia had submitted a new written proposal but Ukrainian President Volodymyr Zelenskiy said he had neither seen nor heard about it.
It remains unclear whether the two sides can revive their faltering peace efforts, more than eight weeks after Russia launched its invasion of Ukraine.
In separate comments on Friday, Lavrov, who has previously accused Ukraine of dragging out the peace process, sounded a downbeat note about the peace talks.
"They have now stalled because our latest proposal that was handed to the Ukrainian negotiators some five days ago and formulated taking into account the comments we received from them remains unanswered," Lavrov told a briefing.
Russian President Vladimir Putin told European Council President Charles Michel in a phone call earlier on Friday that Ukraine was showing it was not ready to seek mutually acceptable solutions and he accused officials in Kyiv of being "inconsistent" in the negotiations.
After making some apparent progress in March, the atmosphere around the peace talks soured over Ukrainian accusations that Russian troops carried out atrocities in a town near Kyiv as they withdrew from the area.
Russia has denied the accusations, saying they were designed to derail peace efforts and serve as a pretext for more foreign sanctions against it.
Russia sent tens of thousands of troops into Ukraine on February 24 in what it calls a "special operation" to degrade its neighbour's military capabilities and root out people it views as dangerous nationalists.
United Nations Secretary-General Antonio Guterres will visit Russian President Vladimir Putin in Moscow on Tuesday to discuss urgently bringing peace to Ukraine, a spokeswoman said.
Guterres will also have a working meeting and lunch with Russian Foreign Minister Sergei Lavrov, spokeswoman Eri Kaneko told a press briefing in New York on Friday.
"He hopes to talk about what can be done to bring peace to Ukraine urgently," Kaneko said.
The secretary-general's office is also working with Ukraine's government on scheduling and preparations for a visit to Kyiv, the spokeswoman said.
Guterres on Tuesday asked Putin to receive him in Moscow and Zelenskiy to receive him in Kyiv, in separate letters handed to their countries' permanent missions to the United Nations.
Guterres on Tuesday also called for a four-day Orthodox Easter humanitarian pause in fighting in Ukraine beginning on Thursday to allow for the safe passage of civilians from areas of conflict and the delivery of humanitarian aid to hard-hit areas.
"The secretary-general is not so much disappointed that his own personal call was not heeded but more that there has been no truce, that civilians cannot leave besieged areas and that the aid that the UN and our partners are ready to deliver to these besieged areas cannot go in," Kaneko said on Friday.
Guterres will further those discussions during his visit to Moscow, the spokeswoman added.
The Pentagon said it expects more than 20 countries will attend US-hosted defence talks in Germany next week to consider Ukraine's long-term defence relationships once the war is over.
Pentagon spokesman John Kirby appeared to play down expectations of announcements about long-term assistance at the April 26 talks, saying: "We're not going into this with a pre-cooked set of endings here."
He added that about 40 countries were invited to attend the talks, which were not being organised under the NATO alliance umbrella, and include non-NATO members.
