Chief Cabinet Secretary Yoshihide Suga spoke on Wednesday about Iran's move, which is intended to counter US economic sanctions, NHK reported.
Suga said Japan hopes to play a constructive role at this difficult juncture. He stressed that the country is a US ally and also maintains good relations with Iran.
He said Japan will continue to pursue dialogue and make every diplomatic effort to alleviate tensions in the Middle East, and promote peace and stability in the region.
The remarks came on Wednesday after Iran announced that it will start to inject gas to Fordow nuclear site on Tuesday.
The deal allowed the first-generation IR-1 centrifuges at Fordow to spin without uranium gas.
The gas injection process took place on Wednesday under the supervision of inspectors from the International Atomic Energy Agency (IAEA). The UN nuclear watchdog is tasked with monitoring the technical aspects in the implementation of the Joint Comprehensive Plan of Action (JCPOA).
An IAEA spokesman confirmed that UN inspectors are on the ground in Iran and will report back on relevant activities.
The Islamic Republic says the suspension of its commitments is not a violation of the JCPOA but is based on Articles 26 and 36 of the agreement itself.
The fate of the Iran deal has been in doubt since May 2018, when the US abruptly abandoned the deal and reinstated the anti-Iran sanctions that it had lifted as part of the JCPOA.
Tehran says the European cosignatories — Britain, Germany and France — have so far failed to uphold their commitments.They have expressed vocal support for the deal, but failed to provide meaningful economic incentives as required under the nuclear agreement.
MNA/PR