Russian forces threatened to encircle a key eastern Ukrainian city, On Wednesday,   saying the West must lift sanctions over its invasion to end a global food crisis.

According to Ukrainian officials, fierce fighting has reached the outskirts of the industrial hub of Severodonetsk, which has been relentlessly bombarded by Russian forces attempting to seize control of the Donbas region.

As the Russian invasion entered its fourth month, Ukraine’s President Volodymyr Zelensky called for more Western support for his outgunned troops, while his foreign minister slammed NATO for doing “nothing.”

Kyiv meanwhile accused Moscow of “blackmail” over its proposal to allow grain exports if the West lifts sanctions, as the war between two of the world’s big wheat producers creates growing food shortages.

The governor of the eastern Ukrainian region of Lugansk, Sergiy Gaiday, described the situation around of Severodonetsk as “very difficult” and said there was “already fighting on the outskirts”.

“Russian troops have advanced far enough that they can already fire mortars” on the city, he said.

Western funds and weapons have helped Ukraine hold off its neighbour’s advances in many areas, including the capital Kyiv.

But Russia is now focused on expanding its gains in eastern Donbas, home to pro-Russian separatists, as well as the southern coast. Donbas comprises Lugansk and the region of Donetsk.

Russia’s February 24 invasion of its pro-Western neighbour has caused global shockwaves, with the latest being fears of food shortages, particularly in Africa.

Moscow blamed the international sanctions imposed after the invasion, while the West says the shortage is mainly down to Russia’s blockade of Ukrainian ports.

“Solving the food problem requires a comprehensive approach, including the removal of sanctions that have been imposed on Russian exports and financial transactions,” said Russian deputy foreign minister Andrey Rudenko.

Ukrainian Foreign Minister Dmytro Kuleba urged the West not to give in.

“This is clear blackmail. You could not find a better example of blackmail in international relations,” Kuleba said at the World Economic Forum in Davos.

Kuleba also slammed the western military alliance NATO for “doing literally nothing” to stop Russia.

Ukraine’s Zelensky urged the West to send more heavy weapons and urged Hungary to stop blocking an EU-wide embargo on Russian oil.

“Unity is about weapons. My question is, is there this unity in practice? I can’t see it. Our huge advantage over Russia would be when we are truly united,” Zelensky said via videolink to an event on the Davos sidelines.

He said in daily address to the nation late Tuesday that Russian forces “want to destroy everything” in eastern Ukraine.

In the eastern town of Soledar, Ukraine’s salt manufacturing hub, the ground shook moments after Natalia Timofeyenko climbed out of her bunker to reassure herself that she was not alone.

“I go outside just to see people. I know that there is shelling out there but I go,” the 47-year-old said after a thundering blast smashed apart a chunk of a mammoth salt mine where she worked with most of her friends and neighbours.

Ghostly frontline towns like Soledar are being hammered by Russian artillery as they sit along the crucial road that leads out of besieged Severodonetsk and its sister city Lysychansk.

Twelve people were killed by “extremely heavy shelling and attacks” in the neighbouring region of Donetsk, which also forms part of Donbas, the Ukrainian presidency said.

In a sign that the rest of the country remains at risk, Russian cruise missiles struck the major southern rail hub of Zaporizhzhia, killing one person and damaging dozens of houses, the presidency added.

Russia meanwhile sought to tighten its grip over the parts of southern Ukraine that it occupies.

President Vladimir Putin on Wednesday signed a decree simplifying a procedure to obtain a Russian passport for residents of the southern Ukrainian regions of Kherson, under the full control of Russian troops, and partly-occupied Zaporizhzhia.

Kyiv said the plan was a “flagrant violation” of Ukraine’s sovereignty.

Residents expressed concerns about the future in Kherson. Moscow-backed officials are pushing for formal annexation by Russia.

“People are very apprehensive,” trolleybus driver Alexander Loginov, 47, told AFP from the cabin of his vehicle, during a press trip organised by the Russian defence ministry.

Day-to-day life remains marked by uncertainty, especially overpayment of salaries as “Ukrainian banks are closing”.

“To be honest, it is just war,” Loginov added.

And 200 bodies were found in the basement of a destroyed building of the port city of Mariupol, which fell to Moscow recently after a devastating siege, Ukrainian authorities said.

The Russian emergency workers simply left the scene after the locals refused to collect and pack the heavily decomposed bodies, according to Ukrainian Ombudswoman Lyudmyla Denisova on Telegram Wednesday.

“It is impossible to be within the area due to the corpse smell,” she wrote. “The occupiers turned the entire Mariupol into a cemetery.”