Visa Inc. and MasterCard Inc., the world’s biggest payments networks, halted services to Crimea after the U.S. escalated sanctions in response to Russia’s annexation of the peninsula and its activities in Ukraine.

The card firms are responding to an executive order from the Obama administration last week, according to emails Friday from the companies’ Russian press offices.

“Visa is now prohibited from offering Visa-branded products and services to Crimea,” the company said. “This means that we can no longer support card-issuing and merchant/ATM acquiring services in Crimea.”

Visa and MasterCard are caught in the middle of an international dispute sparked by Russian President Vladimir Putin’s move to annex Crimea from Ukraine. The firms stopped processing payments at four Russian banks in response to U.S. sanctions earlier this year. Russia then passed a law creating its own national payment system and imposing rules for foreign firms that include fines for denying services. (Bloomberg)