MOSCOW — The Kremlin said on Saturday it wanted a definitive response from Ukraine to Russia's offer of a three-day ceasefire this week, criticizing the reaction so far as ambiguous and historically wrong.

Russian President Vladimir Putin has declared a truce from May 8 to 10 to mark 80 years since World War II victory.

Ukrainian President Volodymyr Zelensky appeared to rule out such a brief ceasefire earlier on Saturday, saying he was only ready to sign up to a ceasefire that would last at least 30 days, an idea Putin has said needs a lot of work before it could become a reality.

Zelensky also said Ukraine, given the continued conflict with Russia, could not guarantee the safety of any foreign dignitaries who came to Moscow for the May 9 parade.

Russia's Foreign Ministry said his comments amounted to a threat, while Dmitry Medvedev, deputy chairman of Russia's Security Council, said nobody could guarantee that the Ukrainian capital of Kyiv would survive to see May 10 if Ukraine attacked Moscow during the May 9 celebrations.

Kremlin spokesman Dmitry Peskov convened a special conference call after Zelensky's comments.

He told reporters that Putin's three-day offer had been a test to assess Kyiv's readiness for a peaceful settlement to end the conflict.

"The reaction of the Ukrainian authorities to Russia's initiative to introduce a ceasefire is a test of Ukraine's readiness for peace. And we will, of course, await not ambiguous but definitive statements and, most importantly, actions aimed at de-escalating the conflict over the public holidays," Peskov said.

He accused the Ukrainian authorities of espousing "neo-Nazism", an allegation Kyiv has repeatedly rejected as false, and of not considering the victory over Nazi Germany to be important enough to mark properly.

In a film published on Sunday by state television about Putin's 25 years as Russia's paramount leader, he was asked by a reporter about the risk of nuclear escalation from the Ukraine crisis.

"They wanted to provoke us so that we made mistakes," Putin said. "There has been no need to use those weapons ... and I hope they will not be required."

Russia has "enough strength and means to bring what was started in 2022 to a logical conclusion", he added.

Fighting continues

On the ground, Russian shelling killed two people in the eastern Donetsk region on Saturday, while a drone strike on the southern city of Kherson left one more person dead, regional officials said.

Meanwhile, Russian authorities accused Ukraine of an overnight attack on the southern port city of Novorossiysk, damaging apartment buildings and injuring five people.

In another development, US officials have finalized new economic sanctions against Russia, including banking and energy measures, to intensify pressure on Moscow to end the conflict, according to three US officials and a source familiar with the issue.

The targets include state-owned Russian energy giant Gazprom and major entities involved in the natural resources and banking sectors, said an administration official, who like the other sources requested anonymity for discussing the issue.

The official provided no further details, Reuters reported.

Agencies Via Xinhua