The relationship between the United States and Russia is deeply strained, with recent disagreements over weighty matters like the Syrian conflict, arms control, human rights and the granting of asylum to Edward J. Snowden, the former National Security Agency contractor who has leaked troves of documents detailing the government’s eavesdropping programs.

Now the two countries are skirmishing over an unanticipated, but no less momentous subject, at least in certain parts of the United States: the delivery of Greek yogurt to the American athletes competing at the Winter Olympics in Sochi.

The Russian government is apparently blocking a shipment of 5,000 containers of Chobani yogurt — now sitting in limbo in cold storage near Newark Liberty International Airport — that had been bound for the United States Olympic team.

The blockade has prompted protests from yogurt-promoting politicians in New York and in Washington, who express outrage that American athletes could be deprived of a protein-rich food that had been part of their training regimen.