It is the second time this week that Tehran has announced a measure that undermines the nuclear accord, which has been in trouble since Trump pulled the United States out of it past year.
"Our level of enrichment will no longer be at 3.67%", he said.
"We have been consistent and clear that our commitment to the nuclear deal depends on full compliance by Iran".
Major General Hossein Salami on Wednesday said Iran had "completely closed the path for the enemy" in the military sphere, Iran's Fars news agency reported.
Rouhani says Iran will increase its uranium stockpile to "any amount that we want" from this Sunday.
Kelsey Davenport, a non-proliferation specialist at the Arms Control Association in Washington, said on Twitter that Iran was "seeking leverage, not dashing for a bomb" by exceeding the uranium limit.
"One of the issues of disagreement between the foreign minister and the oil minister is the former's belief that Zanganeh and oil ministry staffers are not interested in the presence of Asian and Oriental companies in the Iranian petrochemical and oil markets", Abu Torabi said.
"These are political decisions to increase leverage".
The extra uranium build-up so far does not appear to bring Tehran in a significant way towards making a nuclear bomb.
His tone was unusually tough.
Last month the United States came as close as it has ever come to bombing Iran, when President Donald Trump aborted a retaliatory air strike minutes before impact. However, last year, Donald Trump-led USA government had withdrawn from the deal, terming it as "defective at its core". Mysterious attacks have struck oil tankers near the Strait of Hormuz, which the US and Israel blame on Iran, although Tehran denies involvement.
US officials have argued that American sanctions should be no excuse for Iran to increase its enrichment levels, with the White House going a step further on Monday by saying that Iran should not be allowed to enrich uranium at all.
Iran further drove its diplomatic advantage, saying on Monday that the extra uranium build-up was reversible if the European Union did more, while insisting it had not breached the nuclear deal. "He announced that Iran would swell its nuclear stockpile "in any amount that we want, any amount that is required, we will take over 3.67", Rouhani told a cabinet meeting in Tehran, referring the 3.67% enrichment figure specified in the deal".
Mr Rouhani said Iran will also deliver on its threat to resume construction of a heavy water reactor after July 7 and will bring it to the condition that "according to you, is unsafe and can produce plutonium".
Enriched uranium is used to make reactor fuel, but can also potentially be used to produce nuclear weapons. "We will return to that unless you take action regarding all your commitments regarding Arak".
On Monday, Iran's Foreign Minister, Mohammad Javad Zarif, said that Iran's low-grade enriched uranium stockpile has exceeded 300 kg for the first time since Iran reached an agreement with the world powers in 2015 to curtail its mass product.