US President Barack Obama has ordered his administration to take steps towards lifting sanctions on Iran in accordance with the Joint Comprehensive Plan of Action (JCPOA) reached between Tehran and the P5+1 group of nations in July.

"I hereby direct you to take all appropriate additional measures to ensure the prompt and effective implementation of the US commitments set forth in the JCPOA, in accordance with US law," Obama said in a memorandum on Sunday, AFP reports.

The directive comes 90 days after the UN Security Council endorsed the historic nuclear agreement with Iran.

Obama said the measures will take effect after the US secretary of state confirms that Iran has met its commitments under the JCPOA.

"This is an important day for all of us and a critical first step in the process of ensuring that Iran's nuclear program will be exclusively for peaceful purposes," Secretary of State John Kerry added in a statement.

US officials believe that the nuclear deal will take a few months to be implemented.

“For us it's important that it's done right, not that it's done quickly,” a senior Obama administration official told reporters. “We cannot imagine less than two months.”

The JCPOA won final approval in Iran on Wednesday when the Guardians Council, a top panel of jurists and clerics, gave the go-ahead for its implementation.

Iranian lawmakers have also endorsed the nuclear agreement, giving the administration the green light to voluntarily implement the Vienna accord.

In accordance with the JCPOA, Iran has agreed to reduce its uranium enrichment program in exchange for the removal of all economic sanctions.

The European Union also adopted legislative framework Sunday for lifting all of its nuclear-related economic and financial sanctions against Iran.

Iranian Foreign Minister Mohammad Javad Zarif and EU Foreign Policy Chief Federica Mogherini are expected to make statements on the lifting of sanctions.

The Republican opponents of the nuclear deal failed in September to torpedo it in Congress.