Iran's Foreign Minister Mohammad Javad Zarif has called on the United States to choose diplomacy over intimidation and to fulfil its obligations under a year-old nuclear deal with world powers.

"The Iran Deal was a triumph of diplomacy over coercion," Zarif wrote on Twitter late Thursday, the first anniversary of the July 14, 2015 accord with Washington and five other major powers.

"Same stark choice for US today, and reminder: old methods produce same old failures.

"Progress will remain elusive as long as short-sighted bragging, lacklustre implementation of obligations and tired slogans are preferred.

"Mutual respect and fulfilment of JCPOA obligations to ensure promised dividends will open new horizons," he added, referring to the deal by its official name, the Joint Comprehensive Plan of Action.

The agreement, which took effect in January, saw Tehran limit its controversial atomic programme in return for the lifting of nuclear-related sanctions.

It has faced opposition from ultra-conservatives in Iran and the United States.

Iran has complained that remaining sanctions related to its missile programme and support for armed movements like Lebanon's Hezbollah are locking it out of the international banking system and hampering its ability to make major purchases, such as aircraft.

The sanctions are also hindering foreign investment.

US Treasury Secretary Jacob Lew said Thursday that Washington was meeting its commitments under the deal.

But he stressed that the United States would continue to apply sanctions pressure on the country over its alleged support for terror activities and its ballistic missile programme.