The United States is working with Ukraine on a "Plan B" to get grain exports out of the country following Russia's attack on the port of Odesa, according to United States Agency for International Development Administrator Samantha Power.
"Plan B involves road and rail and river and sending in barges and adjusting the rail systems so that they're better aligned with those in Europe so that the exports can move out more quickly," Power told CNN's Larry Madowo in an interview in Nairobi, Kenya on Sunday, after visiting drought-stricken areas of Kenya and Somalia last week.
"We have been living the contingency plan because there's no way you can trust anything that Vladimir Putin says," she continued.
Power stressed that despite the security afforded by a contingency plan, "there is no substitute for Putin allowing the blockade to end and the grains being sent out the most efficient way possible."
On Friday, Russia and Ukraine signed a deal allowing for the export of Ukrainian grain through the Black Sea after months of tough negotiations, mediated by Turkey and the United Nations.
However just one day later, Russia carried out a missile strike on the southern Ukrainian port of Odesa, where vital grain stocks have been lying in storage.
More than half of Somalia's wheat imports come from Ukraine, said Power, adding that 20 million metric tons of wheat and corn are still trapped at the port of Odesa.
Power said she hopes that that the grain deal "somehow sticks" despite Russia's move to "immediately turn its back" on it by bombing the port.
Ensuring the supply of grain will help drive down prices, Power said.
"Even the specter of this deal working and being enforced and the grains leaving the port brought prices down, even in a 24-hour period," she said. "So, more supply with the same amount of demand is going to mean lower prices."
Last week, the US announced an additional $1.3 billion in humanitarian assistance to the Horn of Africa, with unprecedented drought across Ethiopia, Kenya and Somalia.
Power called on countries that play "leadership roles in the international system, such as the People's Republic of China clearly aspires to do," to "dig deeper" to prevent the food crisis "from becoming a catastrophe."