Ben Wallace also called on the country to let Ukraine export its grain.
In comments reported by the Reuters news agency, Mr Wallace told reporters in Madrid the Russian army was “exhausted and broken” but he warned the Russian Navy will be “more of a threat” in the future.
Russia must also “do the right thing” and open a grain corridor from Ukraine’s Black Sea ports, he told reporters in Madrid as he met his Spanish counterpart Margarita Robles at a conference.
Russian officials have said they would be ready to provide a corridor for vessels carrying food to leave Ukraine in return for the lifting of some sanctions.
Mr Wallace rejected the idea of lifting sanctions but he welcomed the suggestion of Black Sea nations, such as Turkey, escorting the Ukraine grain shipments after Moscow ruled out the involvement of Western forces.
“That grain is for everyone, Libya, Yemen, people around the world are relying on that grain to feed themselves,” he said.
“I call on Russia to do the right thing in the spirit of humanity and let the grain of Ukraine out, stop stealing the grain for its own means. Let’s not talk about sanctions, let’s do the right thing.”
Ukraine’s Black Sea ports have been blocked since Russia sent thousands of troops into Ukraine on February 24 and more than 20 million tonnes of grain are stuck in silos in the country.
The British Ministry of Defence said Wednesday that the lack of shipping activity out of Odessa since the start of the war and Russia’s naval blockade of Black Sea ports was likely to increase the price of basic foodstuffs.
“Fighting has already placed indirect pressure on global grain prices,” it said in an intelligence update.
“While the threat of Russia’s naval blockade continues to deter access by commercial shipping to Ukrainian ports, the resulting supply shortfalls will further increase the price of many staple products.”