"We received written guarantees. They are included in the text of the agreement itself on the resumption of the Joint Comprehensive Plan of Action on the Iranian nuclear programme," Lavrov told reporters during a press conference with his Iranian counterpart in Moscow.

More than 10 months of talks in Vienna have brought major powers close to renewing the landmark 2015 Joint Comprehensive Plan of Action (JCPOA) on regulating Iran's nuclear programme.

The negotiations halted after Moscow earlier this month demanded guarantees that Western sanctions imposed following its military incursion into Ukraine would not damage its trade with Iran.

Lavrov told reporters in Moscow on Tuesday that guarantees it had received from Washington would protect Russian involvement in Iran's sole Bushehr nuclear energy plant.

Lavrov said Moscow and Tehran share the position that Western sanctions are imposed with the aim of overriding international law and accused Washington and its partners of directing the penalties "primarily against ordinary citizens".

The 2015 deal gave Iran sanctions relief in exchange for curbs on its nuclear programme.

The agreement aimed to ensure Iran would not be able to develop a nuclear weapon, which it has always denied seeking.