At the same time, the USA retains sanctions against Iran on the missile program, human rights and on suspicion that Tehran sponsors terrorism.
But while acknowledging that the deal would remain in place, the administration imposed modest new sanctions against several Iranian individuals and four organizations, including a China-based network that supplied missile-related items to a key Iranian defense entity.
This is published unedited from the IANS feed.
Iran Foreign Ministry spokesman Bahram Qasemi was quoted as saying."Iran condemns United State's unacceptable ill will in its effort to undermine the positive outcome of Tehran's commitment to implement the nuclear deal by adding individuals to its list of unilateral and illegal sanctions".
Iranian officials say the country has carried out the missile tests as part of its program to boost defense capabilities, rejecting claims that the tests were in violation of Resolution 2231.
Former U.S. Secretary of State John Kerry along with other top security experts have come to defend the Iran nuclear deal, also known as the JCPOA, from the country's hardline President Donald Trump.
The U.S. will continue to "scrutinize Iran's commitment" to the nuclear deal while developing a "comprehensive Iran policy", Acting Assistant Secretary of State for Near Eastern Affairs Stuart Jones said in a statement.More news: U.S. stocks fall sharply on Trump woes; Dow -1.8%
Trump imposed new penalties on seven Iranian and Chinese people and companies regarding the Islamic Republic's ballistic missile program.
In return, Iran has pledged to restrict its nuclear activities, reducing its uranium enrichment, plutonium production plans, and allowing inspectors access to facilities. Chinese complaints come despite worldwide recognition of the destabilising effect both Iran and North Korea have.
The administration's announcement came before Iran holds a presidential election on Friday, and it's unclear if Trump's strident rhetoric - and the fate of the nuclear deal - will shape the outcome.
The Trump administration has said that it is continuing to study the Iran nuclear deal, leaving a door open to leaving it at some point.
In another attempt to ramp up pressure on Tehran, the State Department released a new report criticizing Iran for human-rights abuses, including its alleged mistreatment of prisoners.
The waiver extension comes as Iranian President Hassan Rouhani, whose government pushed hard to achieve the deal, faces off with his rivals in the campaign run for the May 19 presidential vote.
Also designated for sanctions was Chinese national Ruan Runling, who the Office of Foreign Assets Control said has "provided, or attempted to provide, financial, material, technological, or other support for, or goods or services in support of Iran's Shiraz Electronics Industries".