(CNN) The Biden administration is working closely with European allies to try to develop routes to get Ukrainian wheat and corn out of the country after Russia blocked Ukrainian ships from departing with grain that is vital for food supplies around the world, particularly in Africa and the Middle East.
There is no silver bullet to solve the complicated challenge, and officials are considering a wide array of options to get the food exports safely out by rail, sea and air, two US diplomats and four European diplomats told CNN. Possible scenarios are being studied and devised whether Russia consents or not.
The challenge will be a major focus for US Secretary of State Antony Blinken when he convenes a ministerial meeting on food security and chairs a discussion on the matter at the United Nations in New York on Wednesday and Thursday, the diplomats said.
"This is far from a done deal. There are so many moving pieces, so many things could go wrong with these discussions," another official familiar with the discussions said.
Amid concerns about a global food shortage, urgency around the effort is growing as prices for wheat, grain, corn, soybeans and vegetable oil have soared in recent weeks due to Russia's invasion. However, there is no simple solution available with major obstacles to all modes of transport as the war shows no sign of letting up.
Time is of the essence: Ukraine is set to run out of storage facilities for agricultural products in the next two months, explained an official from the World Food Program. If there is no movement in the coming months, Ukrainian farmers will have no place to store next seasons' crop and they will be not paid enough to sustain their businesses.
Before the war, wheat supplies from Russia and Ukraine accounted for almost 30% of global trade, and Ukraine is the world's fourth-largest exporter of corn and the fifth-largest exporter of wheat, according to the US State Department. The United Nations World Food Program -- which helps combat global food insecurity -- buys about half of its wheat from Ukraine each year and has warned of dire consequences if the Ukrainian ports are not opened up.
The issue was a key focus at both the G7 Foreign Ministers meeting in Germany and the US-EU Trade and Technology Council in France over the weekend.
"We must not be naive. Russia has now expanded the war against Ukraine to many states as a war of grain," German Foreign Minister Annalena Baerbock said on Saturday after the G7 meeting. "It is not collateral damage, it is an instrument in a hybrid war that is intended to weaken cohesion against Russia's war."
In a joint statement released following the meeting, the G7 foreign ministers said they are "determined to contribute additional resources to and support all relevant efforts that aim to ensure availability and accessibility of food, energy and financial resources as well as basic commodities for all." The foreign ministers also called for Russia to "cease immediately its attacks on key transport infrastructure in Ukraine" to enable the export of agricultural products.
"There are discussions ongoing at this moment to see how these corridors can be unblocked. We know that mines have been placed in the Black Sea. The Russians have blocked Ukrainian ships from moving in -- or out. And this is something that the secretary general has addressed with the Russians. It's something we have been discussing as well with the Ukrainians: how we can work to get some of the product that is available to Ukraine out into the marketplace," said US Ambassador to the UN Linda Thomas-Greenfield on Monday, explaining that Ukraine used to be a "breadbasket for the developing world."
Although UN Secretary General Antonio Guterres discussed the problem when he met with Russian President Vladimir Putin last month, there have been no breakthroughs. Some US and European diplomats want the UN to play a more active role, but the organization is hesitant due to the ongoing combat, US and European diplomats said.
The most efficient way to transport the grain would be to ship it, but Russia's blockade represents a huge challenge. Sea routes are still under consideration, possibly using neutral UN-marked boats, the sources said. But there are concerns about how practical it would be to test such an idea with an aggressive Russia, diplomats said.
"The Black Sea is not entirely ruled out but it's pretty complicated," one said, adding that Guterres has been actively involved in those preliminary discussions on getting goods out by ship.
Using cargo planes is the least likely of the three options, the official added, due to the dangers in the air and their relatively small capacity compared to trains and ships.
Russia has managed to seal off Ukraine's access to the Sea of Azov but Ukraine retains control over its Black Sea coastline and the port of Odesa, its primary maritime export hub. Still, due to Russian aggressions, ships are not leaving Odesa right now. Russia has also struck the port with missiles and the presence of Russian and Ukrainian mines makes in the sea makes voyages dangerous.
Turkey -- which is a major player in the Black Sea and controls access to it -- is involved in the discussions with the Russians on this effort, said a US official and another source familiar with the ongoing conversations.
"There is a swathe of diplomacy on applying pressure to Russia to encourage safe corridor and that's where the UN has more focus," a European diplomat said.
The diplomats tell CNN that one solution would be to ship the grain via rail given that, for now, it's the safest way to transport large volumes. Talks also are taking place between Ukraine and the European Union about using rail to transport supplies into Romania, Slovakia and Poland. However, the efforts are being complicated by differences in the rail systems used by Ukraine and neighboring countries.
While Ukraine's routes out of the country are limited, Russia is actively sabotaging agricultural production and its forces are stealing farm equipment and thousands of tons of grain from Ukrainian farmers in areas they have occupied, as well as targeting food storage sites with artillery, Ukrainian officials have said.
The $40 billion in supplemental assistance to Ukraine, passed by the US House of Representatives but awaiting passage by the US Senate, includes more than $5 billion to address global food insecurity caused by the war. The bulk of that funding will go to the US Agency for International Development "to provide emergency food assistance to people around the world suffering from hunger as a result of the conflict in Ukraine and other urgent humanitarian needs of populations and communities inside Ukraine," according to a summary from the House Appropriations Committee.
In an interview with CNN last week, Lithuanian Foreign Minister Gabrielius Landsbergis floated the idea of providing a security corridor so that the Ukrainians can export their wheat and corn, saying, "that could be done by the countries who are affected by the food crisis."
Daria Kaleniuk, a leading Ukrainian civil society activist, said that "the quickest and the most sustainable way to global food security is to unblock Ukrainian ports," and called on the international community to provide Ukraine with the weapons needed to militarily help do so.
"We need anti-ship missiles in Ukraine to deter Russian warships, and we need intervention of the UN and other countries and nations which have to regain control over international waters," she said at a roundtable with reporters at the German Marshall Fund in Washington last week.
Meanwhile, concerns about the looming food crisis have been exacerbated by the announcement by India that it will ban wheat exports due to concerns over drought in the country. Thomas-Greenfield said on Monday that the US hoped that India would "reconsider that position" as they hear concerns from around the world.