Ukraine’s military has struck a Russian Karakurt-class small missile carrier on the Caspian Sea off Russia’s distant Dagestan region, the Ukrainian general staff said on Thursday. The port of Kaspiysk where the ship was reportedly located is more than 1,500km from Kyiv – and closer to Tehran, the Iranian capital. The extent of the damage was being assessed, the Ukrainian general staff posted online. Among its armaments, the Karakurt class can fire Kalibr cruise missiles which Moscow has used to hit civilian targets in Ukraine.

Voldoymyr Zelenskyy, the Ukrainian president, expressed satisfaction at the long-range attack and the second assault in eight days on a Lukoil-owned refinery in Perm, near the Ural Mountains. “In a mirror response to Russian strikes, we will continue our long-range sanctions. And in response to Russia’s willingness to move toward diplomacy, we will proceed along the path of diplomacy,” Zelenskyy said.

Ukraine’s purchase of Saab-made Gripen fighter jets could be signed within months, Kyiv’s defence minister said on Thursday as he visited his Swedish counterpart in Stockholm. The countries last year signed a letter of intent that could see Sweden supply up to 150 Gripens. The first deliveries are estimated at three years away from any deal being finalised. “We have our plan how to finance it,” said Mykhailo Fedorov, the Ukrainian defence minister. The Swedish minister, Pal Jonson, said a deal to loan, sell or gift existing Gripens of an older model, to be delivered much faster, was progressing well.

Moscow has issued increasingly shrill protests and threats as its Victory Day parade on Saturday approaches. Foreign ambassadors have meanwhile rebuffed Russian warnings to evacuate their staff from Kyiv in case Moscow decides to attack. Ukraine has never directly targeted Victory Day commemorations, which this year will not even feature military equipment. Russian authorities have demanded a ceasefire and threatened direct strikes on Kyiv if the parade is attacked.

Britain’s Foreign Office said Moscow’s threats toward diplomats in Kyiv were “unwarranted, irresponsible and completely unjustified”, adding that any attack on a diplomatic mission would be a further escalation in the war. The German foreign minister, Johann Wadephul, told Bloomberg TV earlier that Berlin would not pull its embassy staff out Kyiv. Zelenskyy would stay in Kyiv over the weekend, a senior source close to the Ukrainian president told Agence France-Presse.

Zelenskyy said on Wednesday that Moscow wanted a “permit” from Ukraine “to hold their parade, to go out on to the square safely for an hour once a year, and then continue killing, killing our people and waging war … The Russians are already talking about strikes after May 9. Strange and certainly inappropriate of the Russian leadership.” “We have also received messages from some states close to Russia, saying that their representatives plan to be in Moscow,” said Zelenskyy. “A strange desire … in these days. We do not recommend it.”

Throughout the war, Ukrainian drones have regularly harassed the regions around Moscow and cause shutdowns of its airports. On Thursday morning the Moscow mayor, Sergei Sobyanin, said Russian air defence units intercepted more than 50 drones headed for Moscow over a period of about 15 hours. There was no way to confirm the claim. Zelenskyy said Russia had continued to flout a ceasefire starting from the night of 5-6 May that he had proposed in response to the self-declared Russian ceasefire for Victory Day. Ukraine, he said, had received “only new Russian strikes and new Russian threats”.

Russia complained to Armenia for hosting Zelenskyy this week at a summit of the European Political Community, which was set up after Russia’s full-scale invasion of Ukraine. Maria Zakharova, Russian foreign ministry spokeswoman, said Russians were “accustomed to considering [Armenia] a friendly, fraternal country”. The Armenian prime minister, Nikol Pashinyan, told reporters on Thursday: “Back in 2022-2023 I already stated that, on the issue of Ukraine, we are not an ally of Russia.”

Ukraine’s top negotiator, Rustem Umerov, arrived in Miami for meetings with US negotiators on moving toward a peace accord, Zelenskyy said. Achieving peace in Europe was the best way to honour those who fought against Nazi Germany, said Ukraine’s president. “Just as 81 years ago, so now America can help peace with a just and strong stance against the aggressor,” he said. “And it is important that the American people now view Russia precisely in this way – as an aggressor.”