Ukraine’s President Volodymyr Zelenskyy is expected to call on G7 leaders to do more to support his country’s fight against Russia.
Mr Zelenskyy will address world leaders, including Boris Johnson and Joe Biden, via video link from Kyiv after he urged allies to be “partners not observers” in his nightly address on Sunday.
Meanwhile, Mr Johnson will use Monday’s session in Germany to call for urgent action to help get grain supplies out of Ukraine, with countries across the world suffering from shortages.
Since fighting began, major Ukrainian ports, including Odesa, have been blocked and there have been attacks on farms and warehouses.
Before the war, 10% of the world’s wheat, almost 18% of maize and half of the world’s sunflower were all supplied by Ukraine.
But some 25 million tonnes of corn and wheat is currently at risk of rotting in silos and food prices have surged globally since the war started.
Some 47 million people around the world in countries dependent on Ukrainian exports are at risk of a humanitarian disaster.
On Sunday, missile strikes continued to rain over Ukrainian cities, including Kyiv, and Mr Johnson warned the country is on a “knife-edge”.
Mr Johnson is expected to call for an international solution to the crisis, including finding overland routes for grain exports.
The UK has been urging Turkey, which controls access to the Black Sea, to do more to get grain supplies out by ship.
‘Only Putin can end this futile war’
Mr Johnson will tell G7 leaders later: “Putin’s actions in Ukraine are creating terrible aftershocks across the world, driving up energy and food prices as millions of people are on the brink of famine.
“Only Putin can end this needless and futile war.
“But global leaders need to come together and apply their combined economic and political heft to help Ukraine and make life easier for households across the world. Nothing should be off the table.”
The prime minister also wants G7 leaders to look at the use of grain as a source of biofuel, claiming its use to power vehicles may be reducing availability.
Last week at the Commonwealth Heads of Government Meeting, Mr Johnson announced an additional £372m for countries most impacted by rising global food prices.
Mr Zelenskyy will address both the G7 and NATO summits over the coming days.
Ahead of his speech to the G7 leaders gathered in the Bavarian Alps, the Ukrainian president said he would demand extra defence systems to combat the missile bombardment.
“We need a powerful air defence – modern, fully effective – which can ensure complete protection against these missiles,” he said.
“We talk about this every day with our partners. There are already some agreements. And partners need to move faster if they are really partners, not observers.
“Delays in the transfer of weapons to our state, any restrictions are actually an invitation for Russia to strike again and again.
“The occupiers – these terrorists – must be beaten with all our might so that they do not think they can put pressure and outplay someone.”