Russia wants to split Ukraine into two, as happened with North and South Korea, Ukraine’s military intelligence chief says, vowing “total” guerrilla warfare to prevent a carve up of the country.

President Volodymyr Zelensky urged the West to give Ukraine tanks, planes and missiles to help fend off the Russian forces, which the Kyiv government said were increasingly targeting fuel and food depots.

Meanwhile, US officials continued efforts to soften comments on Saturday from US President Joe Biden, who said in a fiery speech in Poland that Russian leader Vladimir Putin “cannot remain in power”.

US Secretary of State Antony Blinken said Washington had no strategy of regime change in Moscow, telling reporters in Jerusalem that Mr Biden had simply meant Mr Putin could not be “empowered to wage war” against Ukraine or anyone else.

After more than four weeks of conflict, Russia has failed to seize any major Ukrainian city and Moscow signalled on Friday it was scaling back its ambitions to focus on securing the Donbass region of eastern Ukraine, where Russian-backed separatists have been fighting the Ukrainian army for the past eight years.

A local leader in the self-proclaimed Luhansk People’s Republic said on Sunday the region could soon hold a referendum on joining Russia, just as happened in Crimea after Russia seized the Ukrainian peninsula in 2014.

Crimeans voted overwhelmingly to break with Ukraine and join Russia – a vote that much of the world refused to recognise.

“In fact, it is an attempt to create North and South Korea in Ukraine,” Kyrylo Budanov, the head of Ukrainian military intelligence, said on Sunday in a statement, referring to the division of Korea after World War II.

He predicted Ukraine’s army would push back Russian forces.

“In addition, the season of a total Ukrainian guerrilla safari will soon begin. Then there will be one relevant scenario left for the Russians, how to survive,” he said.

Moscow says the goals for what Mr Putin calls a “special military operation” include demilitarising and “denazifying” its neighbour. Ukraine and its Western allies calls this a pretext for an unprovoked invasion.

The invasion has devastated several Ukrainian cities, caused a major humanitarian crisis and displaced an estimated 10 million people, nearly one-quarter of Ukraine’s total population.

In a late-night television address on Saturday, Mr Zelensky demanded that Western nations hand over military hardware that was “gathering dust” in stockpiles, saying his nation needed just 1 per cent of NATO’s aircraft and 1 per cent of its tanks.

Western nations have so far given Ukraine anti-tank and anti-aircraft missiles as well as small arms and protective equipment, but have not offered any heavy armour or planes.

“We’ve already been waiting 31 days. Who is in charge of the Euro-Atlantic community? Is it really still Moscow, because of intimidation?” Mr Zelensky said, suggesting Western leaders were holding back on supplies because they were frightened of Russia.

Ukrainian Interior Ministry adviser Vadym Denysenko said on Sunday that Russia had started destroying Ukrainian fuel and food storage centres, meaning the government would have to disperse stocks of both in the near future.

Appearing to confirm that, the Russian defence ministry said its missiles had wrecked a fuel deposit on Saturday as well as a military repair plant near the western city of Lviv, just 60 kilometres from the Polish border.

In its latest military assessment, the British Ministry of Defence said Russian forces appeared to be concentrating their efforts on encircling Ukrainian troops directly facing separatist regions in the east.

“The battlefield across northern Ukraine remains largely static with local Ukrainian counterattacks hampering Russian attempts to reorganise their forces,” the ministry said.