British Prime Minister Boris Johnson said Thursday that Britain was willing to assist with de-mining operations off Ukraine's southern coast and was considering offering insurance to ships to move millions of metric tons of grain stuck in the country.

Russia's Feb. 24 invasion of Ukraine and blockade of its Black Sea ports has prevented the country, traditionally one of the world's top food producers, from exporting much of the more than 20 million metric tons of grain stored in its silos.

This has helped push food prices to record highs and left tens of millions of people struggling to eat, a crisis which Western officials say could last two years.