TEHRAN, Dec. 24 (Xinhua) -- Kazakh company Kazatomprom has delayed its delivery of uranium to Iran as it is seeking the permission of six world powers involved in the 2015 Iranian nuclear deal, local media reported Sunday.

Galymzhan Pirmatov, Kazatomprom's chairman, was quoted by Financial Tribune daily as saying that the delivery of uranium concentrate to Iran can be possible only after obtaining permission from the six countries involved in the nuclear deal, namely Britain, China, France, Russia, the United States, plus Germany.

Iran and Kazakhstan signed a contract on the supply of natural uranium concentrate to Iran in April 2016.

Based on the deal, Kazatomprom first planned to begin delivery of uranium to Iran this year, but it was delayed due to the process of obtaining permission from the concerned parties.

Kazatomprom has extended the contract with Iran till 2020, and its delivery of uranium to Iran has been rescheduled to the 2018-2020 period, if approved by the six powers, Pirmatov said.

Iran signed with the six powers the nuclear deal in 2015 to halt its nuclear weapons development program in exchange for the lifting of the nuclear-related economic sanctions imposed on it.