Putin has consistently rejected calls to pause his nearly three-and-a-half year assault on Ukraine despite growing pressure from US President Donald Trump, who issued a 10-day ultimatum earlier this week to stop the fighting.

"We need a lasting and stable peace on solid foundations that would satisfy both Russia and Ukraine, and would ensure the security of both countries," Putin told reporters.

But he added that "the conditions (from the Russian side) certainly remain the same".

Russia has frequently called on Ukraine to effectively cede control of four regions Moscow claims to have annexed, a demand Kyiv has called unacceptable.

Ukraine has been pleading with its Western backers to send more weapons for its troops to withstand Moscow's daily attacks and levy more sanctions on Russia and its trading partners.

Ukrainian President Volodymyr Zelensky has been pushing for a meeting with Putin to end the conflict, with Kyiv proposing talks by the end of August.

Zelensky on Friday repeated that call.

"We understand who makes the decisions in Russia and who must end this war," he said on social media.

Ukraine was ready "to meet at the level of leaders at any time", he added.

Putin, speaking alongside Belarusian President Alexander Lukashenko, also said Moscow had started mass producing Oreshnik -- its hypersonic nuclear-capable missile.

Russia used Oreshnik to strike the city of Dnipro in central Ukraine last year before announcing it could deploy the missile in Belarus, its close ally.

"Our specialists, both Belarusian military specialists and Russian specialists, have chosen a place for future positions," Putin said.

"Work is now underway to prepare these positions. So, most likely, we will close this issue by the end of the year," he added.