Iran’s President Hassan Rouhani said the Islamic republic “will proudly bypass sanctions” by the United States that took effect on Monday targeting the country’s oil and financial sectors.

“I announce that we will proudly bypass your illegal, unjust sanctions because it’s against international regulations,” Rouhani said in a televised speech.

“We are in a situation of economic war, confronting a bullying power. I don’t think that in the history of America, someone has entered the White House who is so against law and international conventions,” he added.

The US on Monday unleashed its “toughest ever” sanctions against Iran, a move that has already sparked mass protests in the oil-rich nation.

The renewed US sanctions aim to significantly curb Iran’s oil exports and cut it off from international finance and follow US President Donald Trump’s controversial decision in May to abandon the multi-nation nuclear deal with Tehran.

More than 700 individuals, entities, vessels and aircraft were now on the sanctions list, including major banks, oil exporters and shipping companies.

Washington has also said that it wanted to stop what it calls Tehran’s “malign” activities including cyber attacks, ballistic missile tests, and support for terror groups and militias in the Middle East.

The Trump administration has granted exemptions to eight countries to continue importing Iranian oil, without naming them. They are reported to include US allies India, Italy, Japan and South Korea.

Iran’s biggest oil customers – all in Asia – have been seeking sanctions waivers to allow them to still buy some of its oil.

India last week had said that it was engaged with the US, Iran and other stakeholders on the issue of American sanctions on the import of Iranian oil, amid indications that the Trump administration may grant New Delhi waiver from punitive measures.

Iranian President Hassan Rouhani has, however, vowed to sell his country’s oil and break the sanctions.

Iran’s military has said that it would hold air defence drills on Monday and Tuesday to prove the country’s capabilities.

The UK, Germany and France – which are among the five countries still committed to the nuclear pact – have all objected to the sanctions, the BBC said.

They have promised to support European firms that do “legitimate business” with Iran and have set up an alternative payment mechanism – or Special Purpose Vehicle (SPV) – that will help companies trade without facing US penalties.

On Sunday, thousands of Iranians chanting “Death to America” rallied, rejecting calls for talks.

The rallies coincided with the siege of the US embassy on November 4, 1979, which took place soon after the fall of the US-backed shah.

Some 52 Americans were held hostage in the embassy for 444 days and the two countries have been enemies ever since.

(With agency inputs)