Iran will inform the United Nations nuclear watchdog agency that preparations will begin on Tuesday, Behrouz Kamalvandi, spokesman for Iran's Atomic Energy Organization, was reported saying by state media.
One of Trump's demands - which European allies support in principle - is new negotiations to rein in Iran's ballistic missile program, which was not covered by the nuclear deal.
Under the JCPOA, Iran was limited to enriching uranium to 3.67 percent-enough to use in civilian power plants, but not in weapons.
Before the deal was signed, Iran had reached 20 percent enrichment.
On a visit to Berlin, Mr Netanyahu called on the International Atomic Energy Agency to investigate his claims to have discovered proof of Iran's efforts to build a nuclear weapon.
Iran's announcement that it is getting ready to expand production of uranium hexafluoride is significant since this is the primary feedstock that goes into the centrifuges that spin to enrich uranium.
Netanyahu, on a tour to persuade European countries to follow the United States administration of Donald Trump in tearing up a nuclear non-proliferation deal with Iran, said the country was using proceeds from eased sanctions to finance conflict.
The document was signed on behalf of the Iranian army by Amir Daryaban Ali Shamkami, now the secretary of Iran's national security council and the military adviser to Iran Supreme Leader Ayatollah Ali Khamenei.
In his Monday meeting with German Chancellor Angela Merkel, Netanyahu warned that Iran was "seeking nuclear weapons to carry out its genocidal designs". 'Some Europeans are talking about limiting our defensive missile programme. I am telling the Europeans, 'Limiting our missile work is a dream that will never come true, ' he said in a televised speech.
As for curbing Iran's global influence, the supreme leader stressed that "we will continue our support for oppressed nations".
The Obama-era deal was undermined by President Donald Trump's withdrawal from it at the start of May.
Merkel said they were in agreement with Netanyahu on the need to prevent a nuclear-armed Iran, but had different views on the best way to achieve this.
This is while Iran is now in talks with the other signatories on the future of the deal.
"We are not in agreement on all questions, but we are friends, we are partners", Merkel said of Netanyahu.
Khamenei also said Iran had no intention of curbing its influence in the Middle East as demanded by the Western powers and urged Arab youth to stand up to USA pressure.