Kremlin hits back at Biden's remark on Putin

The Kremlin hit back at United States President Joe Biden's remark during a speech on Saturday that Russian leader Vladimir Putin "cannot remain in power", saying that's not up to Biden because Russia's presidents "are elected by Russians".

Biden made his comment castigating his Russian counterpart during a visit to the Royal Castle in Polish capital of Warsaw after meeting with top Ukrainian ministers.

He participated in intensive NATO, G7 and the European Council summits during his visit to Europe, with the Ukraine crisis as the major focus.

Biden tried to coax a display of unity with European partners, but failed to talk them into concerted actions against Russia.

In his speech, Biden plainly warned Russia not to "think about moving on one single inch of NATO territory", while bluntly calling the Russian president "a butcher".

Biden coupled his harsh words for Putin with a pointed attempt to appeal to ordinary Russians, saying they were "not our enemy" and urging them to blame their president for the heavy sanctions imposed by the West.

Although the White House moved quickly to temper Biden's unprecedented comment on Putin, insisting that the US leader is not seeking "regime change" in Russia and was referring to Putin's influence over neighbors in the region, the Kremlin made its displeasure clear.

Kremlin spokesman Dmitry Peskov said it is not for Biden to decide who should be in power in Russia.

"A state leader should control his temper," Peskov said.

"And, of course, each time such personal insults are uttered, they narrow the window of opportunity for our bilateral relations under the current US administration. It is necessary to be aware of this," Peskov stressed.

Biden met with Ukraine's Foreign Minister Dmytro Kuleba and Defense Minister Oleksii Reznikov earlier on Saturday.

He offered reassurance to Ukrainians at a time when nearly 4 million of them have been driven out of their country.

In a tweet, Kuleba said that the meeting allowed him to seek "practical decisions in both political and defense spheres in order to fortify Ukraine's ability to fight back", while Reznikov tweeted that he felt "cautious optimism".

However, in a possible shift on a plan to transfer Soviet-era fighter jets from Poland to Kyiv to boost Ukraine's firepower in the skies－rejected last month by the Pentagon as too "high risk"－Kuleba said that the United States now did not object.

Biden made clear that the West would need to steel itself for what will be a long and difficult battle.

He cast doubt on Russia's signal that it may scale down its war aims to concentrate on eastern Ukraine, even as two Russian missile strikes had hit a fuel depot in Ukraine's Lviv, a rare attack on a city just 70 kilometers from the Polish border.

Russian Defence Ministry spokesman Igor Konashenkov said on Saturday that Russian Armed Forces destroyed four Ukrainian unmanned aerial vehicles in the past day, including a drone that was flying over the Black Sea toward Sevastopol.

According to Konashenkov, Russia's air defenses also downed a Ukrainian military Mi-24 helicopter over the Staraya Basan settlement, which is 60 km east of Kyiv.

Agencies contributed to this story.