Zakayev made the announcement amid a growing rift between the parliament-in-exile of the self-declared Chechen Republic Ichkeria (ChRI) and the separatist president and resistance commander, Doku Umarov.
In a video statement received by RFE/RL last month, Umarov declared the existence of a "North Caucasus emirate" and proclaimed himself the emir. That declaration prompted the ChRI parliament to state that Umarov had effectively relinquished his presidential powers, which now devolve to the parliament.
Zakayev told RFE/RL by phone from London today that until the parliament makes a decision on forming a new cabinet and appointing a new prime minister, he is not able to continue as foreign minister. "I think that everything that is happening in the state should have a legitimate foundation; everything should be done in compliance with the law, and in this case, I think that until the parliament forms a new cabinet of ministers, neither I nor the other members of the cabinet can fulfill their duties and professional obligations," he said.
Zakayev said his resignation should not be viewed "as a departure from the fight for our independence, our freedom, and for the recognition of our state. By no means."
"Chechnya at present is occupied, but it is not conquered," he continued. "That's why people today are waiting for an opportunity, but they haven't accepted this situation by any means. I am absolutely confident that the Chechen people have good reason to think that soon in the future they will gain independence and live in a free, democratic country."
In a response to Umarov's declaration of a North Caucasus emirate, which included a call to extend the separatist movement's resistance to a broader "holy war" against the West, Zakayev suggested that Umarov had been influenced by Russian operatives seeking to discredit the Chechen leadership.
Aslan Doukaev, the head of RFE/RL's North Caucasus Service, said Umarov’s declaration highlights the rift between radical Chechen separatists following a jihadist philosophy, like Umarov himself, and moderate nationalists such as Zakayev.