An Iranian man marches with a portrait of the country's Supreme Leader Ali Khamenei (L) alongside a woman holding up another of Islamic Revolution founder Ayatollah Ruhollah Khomeini (R) during a ceremony celebrating the 40th anniversary of Islamic Revolution in the capital Tehran on February 11, 2019.
State TV showed crowds defying cold rainy weather and carrying Iranian flags while shouting "Death to Israel, Death to America", trademark chants of the revolution which ousted the United States' most important ally in the Middle East.
On Feb. 11, 1979 Iran's army declared its neutrality, paving the way for the fall of US -backed Shah Mohammad Reza Pahlavi.
In his address on Tehran's Azadi Square, Rohani said the "enemy will never reach its evil objectives", vowing that Iran will defeat US sanctions.
"We have not asked and will never ask anyone for permission to increase our defence capabilities and to build all kinds of missiles, be they surface-to-air missiles, anti-ship missiles or ground-to-ground missiles", the Iranian leader said.
In Washington, US National Security adviser John Bolton, who in 2017 expressed the hope that Iran's "revolution will not reach its 40th birthday", tweeted that after 40 years, the "Islamic Republic of Iran has failed to fulfil its promises to uphold and safeguard the rights of its citizens".
"Our presence in the 40th anniversary of the revolution is to show our support for the Islamic Republic", said one sign held by a protester.
Tensions between Washington and Tehran are high after the U.S. withdrew from an global nuclear deal aimed at curbing Iran's nuclear ambitions, and re-imposed sanctions that have hurt the Iranian economy.
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But Dani Alves may be needed in defence now, after Thomas Meunier suffered a concussion during a Ligue 1 clash against Bordeaux . If we are missing lots of key players, it's an even bigger challenge, but we will be ready on Tuesday, I think".
The Israeli prime minister's comments came in direct response to IRGC political affairs spokesman Yadollah Javani, who warned earlier on Monday that Iran would attack Israel if threatened by Washington.
"The Iranian people have and will have some economic difficulties [due to the sanctions] but we will overcome the problems by helping each other", Rouhani said in his address.
Rouhani was referring to the Kingdom of Bahrain, which Iranian officials in the past have referred to as the "14th province".
Iran and Saudi Arabia are locked in proxy wars in Iraq, Yemen and Syria.
Iran's Islamic revolution four decades ago has been a complete failure for the country, US President Donald Trump said Monday.
State television offered blanket coverage of the commemorations, showing marches in cities ranging from Abadan in southwestern Iran to Mashhad in the northeast.
In a report coinciding with the celebrations, Reporters Without Borders (RSF) said that 61,900 political prisoners had been held in Iran since the 1980s.