TEHRAN, Feb. 11 (Xinhua) -- As Iran on Wednesday is heading into celebrations marking the 36th anniversary of the Islamic revolution with popular rallies, it has still been trying to reach a fine deal with the world powers on its nuclear program.

Hundreds of thousands of people in Iran's major cities swarmed to the streets, carrying flags, banners and images of late founder of the Islamic republic Ayatollah Ruhollah Musavi Khomeini, and his successor, incumbent Supreme Leader Ayatollah Ali Khamenei.

In capital Tehran, people were also waving banners with anti-U.S. and anti-Israel slogans, while chanting support of the country's rights to peaceful use of nuclear power.

Also on Wednesday, Iran rejected again that it is the West-imposed sanctions that have forced the country to negotiate with the powers over its nuclear issue, official IRNA news agency quoted Foreign Ministry Spokeswoman Marzieh Afkham as saying.

"Regarding the peaceful nature of its nuclear program, the Islamic republic has stepped into the nuclear talks to constructively interact (with the world) to put an end to this fabricated crisis," Afkham said.

The sanctions have not forced Iran to enter the talks but "impracticality of all-out pressures against Iran" and "the significant advancements in Iran's peaceful nuclear program" made the United States come to the negotiation table, she added.

Afkham was referring to U.S. President Barack Obama's recent remarks, saying that Iran came to the negotiations due to the sanction pressures.

"Iran has a strong political will to reach a good deal" with the powers, she said, adding that still, the U.S. official have not given up their "excessive demands" which is a barrier for a comprehensive deal.

On Tuesday, one day before the anniversary, Iranian President Hassan Rouhani urged the world powers to seize the opportunity, saying Tehran has already taken major steps in the nuclear talks to reach a final deal.

"Although we haven't reached a final agreement yet, Iran is following nuclear negotiations seriously and good progress has been achieved so far," Rouhani was quoted as saying by official IRNA news agency.

"We have taken the necessary steps and now it is the other side's turn to seize the opportunity," said the Iranian president in a meeting with India's National Security Advisor Ajit Kumar Doval.

The Western powers have accused the Islamic Republic of having been developing atomic weapons under the cover of civilian nuclear plan. Iran rejected the allegations as baseless, and insisted that its nuclear program is solely peaceful.

Also, Rouhani urged the Iranians to actively participate in Wednesday' rallies to show their all-out support for the Islamic establishment, according to semi-official Fars news agency.

The 1979 revolution toppled the U.S.-backed regime of Shah and brought the country under the leadership of Ayatollah Khomeini.

"The February 11 is a day of national celebration and the Iranian nation's day," Rouhani said, adding that "undoubtedly, we can go through economic problems and the nuclear negotiations more easily with the high massive turnout of the Iranian nation in the February 11 rallies."

With the support of people, Iran will tackle all the issues more powerfully and will defend the nation's rights more easily at lower costs, he added.

Iran and the P5+1 group, including the United States, Great Britain, France, Russia, China and Germany, are committed to agreeing on a general framework of the potential deal by the end of March, before heading towards another self-imposed deadline for a final and comprehensive deal by July this year.

Earlier, Iran's Supreme Leader Ayatollah Ali Khamenei said said that he agreed with "an agreement ..., but no-agreement is better than any agreement which undermines the interests of our nation."

The Western powers have imposed rounds of diverse sanctions on Iran, accusing the Islamic Republic of having been developing atomic weapons under the cover of civilian nuclear plan. Iran rejected the allegations as baseless, and insisted that its nuclear program is solely peaceful. Enditem