The conflict in Ukraine is reaching a "critical moment" amid warnings Russia is deliberately driving up global food prices by blocking grain exports, the foreign secretary has warned.
It comes as Kyiv launched a fresh appeal appealing for more weapons to fend off Russian advances in the south and the east.
Speaking in the House of Commons on Thursday, Liz Truss reaffirmed the UK's support for Ukraine, adding that now is a key time for allies to double down behind the country due to questions being raised over whether countries will sustain the support they are providing.
The foreign secretary said the united effort of the UK and its allies to back Ukraine has been vital to its success.
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She said: "We are now reaching a critical moment, Russia is bombarding towns and cities in the east and some outside Ukraine are questioning whether the free world can sustain its support and claiming that some are beginning to tire of this war."
She said the people of Ukraine "do not have that luxury", adding the UK would "never tire" of defending democracy.
In a show of unity the leaders of Italy, France and Germany all met with Ukrainian president Volodymyr Zelenskyy in Kyiv on Thursday.
They vowed to keep on supporting the country, pledging to back Ukraine's bid to be an official candidate to join the EU.
Truss went on: "Russia's efforts to destroy Ukraine will only lead to it becoming a stronger more prosperous more united European nation."
She also attacked Russia for its blockade of Ukraine's ports, which is putting global food supplies in jeopardy.
Truss said the government was working with Ukraine to try and open the port in Odesa – the largest port still in Ukrainian hands.
She said: "What we are doing is working with Ukrainians on shore-to-ship weapons to help protect the port, we are working with the UN both through the general assembly and through other mechanisms to try and secure access to the port."
She added: "We’re doing all we can to get that grain out of Ukraine because it’s vital for the Ukrainian economy but also to deal with the very real issue of world hunger."
Russia has said in the past it is willing to let grain shipments through its blockade, but so far very little is getting out of Ukraine.
Ukraine is one of the world's largest exporters of grain and many nations in Asia and Africa rely heavily on these imports to feed their population.
Agriculture minister Mykola Solskyi said this week the invasion could create a global wheat shortage for at least three seasons by keeping much of the Ukrainian crop from markets, pushing prices to record levels.
On top of the immediate pressure of Ukrainian grain being stuck in the country, there are fears by the time of the next harvest most farms will not be able to operate to anywhere near the capacity they were able to before the war.