TEHRAN, Feb. 11 (Xinhua) -- Iranian President Hassan Rouhani said on Monday that his people will unite to tackle problems created by powers such as the United States.
Iran will not allow the United States to achieve its ends by exerting sanction pressures against the country and creating challenges for Iran in the region, Rouhani told a large gathering at Azadi Square in Iran's capital Tehran on the 40th anniversary of the Islamic Revolution.
"Today, we are facing the cruel enemy's psychological, propagandistic and economic war against the country," Rouhani said.
Iran will emerge victorious against the sanctions of the United States and "we will not allow the United States to succeed," he added.
Over the past year, the U.S. officials vowed, on a number of occasions, to overthrow Iran, but it did not happen and will never happen, said Rouhani.
"Our condition in Iran is much better than they thought," the Iranian president stressed.
Last November, the United States announced re-imposition of full sanctions on Iran covering its oil exports and banking sectors, months after Washington's exit from the 2015 landmark Iranian nuclear deal.
Rouhani also touched upon his country's support to some regional countries, saying its helps have aborted the enemies' plots.
"With Iran's support to Syria, Iraq, Lebanon, Palestine and Yemen, the enemies could not succeed in their plots," Rouhani told the rally.
Some non-regional powers are planning to leave the region for the same reason, he said, alluding to the recent U.S. decision to pull its forces out of Syria.
"Iran is the only state which can help the regional countries," he said, emphasizing that "without Iran, the prospect of success for any plan in the region is dim."
On Monday, hundreds of thousands of Iranians attended nationwide rallies to celebrate the 40th anniversary of the victory of the Islamic Revolution.
The rallies in the Iranian cities were coupled with anti-U.S. sentiments reflected in the slogans.
In the capital Tehran, people swarmed to the streets, chanting anti-U.S. and anti-Israeli slogans and carrying images of Ayatollah Ruhollah Khomeini, late founder of the Islamic republic, and his successor and the incumbent supreme leader Ayatollah Ali Khamenei.
This year's demonstrations come against the U.S. withdrawal from the 2015 Iranian nuclear deal and re-imposition of tough sanctions on the country.
Iran also displayed a number of its ballistic missiles on the streets leading to Azadi Square despite western calls on Iran to halt development of its controversial missile program.
"To build diverse missiles ... we have not sought and will not seek the permission of anybody," Rouhani said.
The advancements in military power of Iran over the past 40 years, particularly during the past five years, have astonished the world, the Iranian president noted.
"We will continue to promote our military power," he concluded.
The 1979 Revolution in Iran toppled the U.S.-backed Shah regime of Mohammad Reza Pahlavi, an event seen as a turning point in Iran's history.