WASHINGTON — President Donald Trump is making an unsubstantiated assertion that the Obama administration granted 2,500 Iranians citizenship as part of a 2015 nuclear deal that sought to limit Tehran's weapons program.

Nothing in the agreement speaks to the naturalization of Iranians. Indeed, according to U.S. naturalization figures, the number of Iranians who were granted citizenship barely increased during final negotiations, actually falling after the July 2015 deal was signed.

A look at the claim:

TRUMP: "Just out that the Obama Administration granted citizenship, during the terrible Iran Deal negotiation, to 2,500 Iranians - including to government officials. How big (and bad) is that?" — tweet Tuesday.

THE FACTS: Trump's claim, which he repeated from a Fox News report, is baseless. The report said Hojjat al-Islam Mojtaba Zolnour, a hardline member of Iran's parliament, had made the allegation in an interview with a local newspaper. He is a vocal critic of the nuclear agreement.

The agreement was signed in July 2015 to significantly limit Tehran's nuclear ability in exchange for lifting international oil and financial sanctions. Nothing in the agreement addresses the naturalization or immigration of Iranians.

Rather than increase, the number of Iranians naturalized in the U.S. declined after the deal was signed, from 10,344 in 2015 to 9,507 in 2016, according to the Department of Homeland Security. In 2014, the number of Iranians who were made citizens was 9,620. There are about a million Iranians living in the U.S., many with green cards, representing a wide pool of residents who can eventually become citizens.

Trump backed out of the Iran nuclear accord in May, describing it as a flawed deal.

EDITOR'S NOTE _ A look at the veracity of claims by political figures