Iran's parliament voted on August 13 to allocate $520 million to develop its missile programme to fight Washington's "adventurism" and sanctions, and to boost the foreign operations of the country's Revolutionary Guards.
Iranian President Hassan Rouhani, who was sworn in for a second term earlier this month, called the nuclear deal "a sign of Iran's goodwill on the worldwide stage". It also comes as a North Korean-announced deadline to fire missiles into the waters around Guam approaches.
Earlier this month, the U.S Congress passed and President Donald Trump signed legislation imposing new sanctions on Iran over its missile program.
"The Americans should know that this was our first action", speaker Ali Larijani said after announcing the voting results - according to the official Islamic Republic News Agency.
Deputy Foreign Minister Abbas Araqchi, who is the head of an Iranian commission tasked with monitoring the agreement's implementation, told MPs that the government backed the bill which he described as "very strong".
During his campaign he threatened to tear up the 2015 nuclear deal with Iran, which he has called "the worst deal ever".
It will also require Iran's government and armed forces to draw up a plan to counter USA violations of human rights around the world and to support Iranian bodies and individuals affected by sanctions.
The bill also imposes sanctions against several United States entities which, Iran says, are involved in supporting terrorism in the Middle East.
A second vote will now take place on the bill before it is submitted to a clerical body for final approval.
Last week, Iranian President Hassan Rouhani warned Mr Trump that he risks political suicide if he scrapped the nuclear deal with Tehran.
To counter USA economic sanctions, the government has been ordered to provide a comprehensive plan on expanding economic cooperation with world countries, especially Iran's neighbors and friends as well as the countries which have likewise been subject to Washington's embargoes.