Russia on Monday declared a unilateral ceasefire with Ukraine between May 8-9, when Moscow marks its annual World War II Victory Day commemorations, and threatened a “massive missile strike” on Kyiv if Ukraine violated it.

Ukraine responded by declaring a truce of its own between May 5-6, saying it was “not serious” to expect it to observe a ceasefire during a Russian military holiday.

The quarrelling between the two sides comes with a lull in US-led diplomatic efforts to end the war, as Washington shifts its focus to conflict in the Middle East.

Russian strikes killed nine people across Ukraine on Monday, according to Ukrainian officials, while a Ukrainian drone crashed into a high-rise building in an upscale Moscow neighbourhood overnight.

“In accordance with a decision of the Supreme Commander-in-Chief of the Russian Armed Forces, Vladimir Putin, a ceasefire has been declared from May 8–9, 2026… We hope that the Ukrainian side will follow suit,” the Russian defence ministry said in a post on state-backed messaging service MAX.

“If the Kyiv regime attempts to implement its criminal plans to disrupt the celebration of the 81st anniversary of Victory in the Great Patriotic War, the Russian Armed Forces will launch a retaliatory, massive missile strike on the centre of Kyiv,” it added.

“We warn the civilian population of Kyiv and employees of foreign diplomatic missions of the need to leave the city promptly.”

Russia marks World War II Victory Day each year with a massive military parade through Red Square.

Ukraine’s President Volodymyr Zelensky said Monday that having a ceasefire so Moscow could mark the celebration was “not serious”, and that Russia was afraid Ukrainian drones would “buzz over Red Square”.

“As of today, there has been no official appeal to Ukraine regarding the modality of a cessation of hostilities that is being claimed on Russian social media,” Zelensky said in a post on X.

“In this regard, we are announcing a ceasefire regime starting at 00:00 (2100 GMT) on the night of May 5–6. In the time left until that moment, it is realistic to ensure that silence takes effect,” he added.

The Ukrainian leader later landed in the Gulf nation of Bahrain for talks on “security cooperation”, a source in the Ukrainian delegation told AFP.

Russian strikes on Ukraine killed at least nine people on Monday, according to Ukrainian officials.

A Russian ballistic missile attack on the town of Merefa – outside Ukraine’s second city of Kharkiv – killed seven civilians and wounded dozens earlier Monday, regional authorities said.

AFP journalists in Merefa saw several bodies strewn in the street, covered by blankets and white sheets – with shops, houses and cars damaged.