TEHRAN, Iran (CNN) -- Iran's nuclear fuel production program has reached "industrial" levels, the country's president said Monday in a speech at the Natanz nuclear facility.
"Iran has succeeded in development to attain production at an industrial level," said Mahmoud Ahmadinejad, addressing an audience that included invited ambassadors of Islamic and non-aligned countries at a ceremony marking the anniversary of the start of uranium enrichment at the plant.
"With great pride, I announce that as of today, our dear country, Iran, is among the countries of the world that produces the industrial level of nuclear fuel."
Ahmadinejad vowed the fuel would be used for energy, "and for the expansion of peace and stability."
He added that the goal of "progress" for Iran was "irreversible."
Earlier, Iranian nuclear chief Gholamreza Aghazadeh said: "We have gathered, thanking Almighty God for the introduction of the uranium enrichment program to the industrial phase, and once again we thank Almighty God for allowing us to attain industrial enrichment plans."
Throughout Iran on Monday, schools also celebrated "National Technology Day," marking the date 27 years ago that Washington severed diplomatic relations with Tehran.
Earlier, Iran's chief nuclear negotiator said Tehran was ready to resume serious negotiations over its nuclear ambitions, Iranian state media reported.
Ali Larijani said Iran hoped to reach an agreement with Western powers that would "remove their worries" without compromising its own scientific development, Iranian state media reported.
"Today, with the nuclear fuel cycle complete, we are ready to begin real negotiations with the aim of reaching an understanding," Larijani was quoted as saying in a speech in the eastern city of Mashad.
"We are ready to negotiate and reach an agreement with Western countries in order to remove their worries about nuclear Iran without putting an end to our scientific development."
Iran has repeatedly said uranium enrichment, which the United Nations has demanded it stop, is its right and will not be abandoned. The 15-member Security Council voted unanimously last month to pass Resolution 1747.
The U.S. and other nations contend that Iran is using the project to develop nuclear weapons, a claim Iran denies.
In Tehran, around 200 students gathered in front of the Atomic Energy Organization, chanting "death to America" and "death to Britain" and burning American and British flags, The Associated Press reported.
Up to 15,000 students also planned to hold hands around the Natanz plant to show their support for "Iran's peaceful ambitions, state-run news agency IRNA said.
Tensions between Iran and the West have also been heightened by last month's seizure of 15 British sailors and marines by Iranian forces while on patrol in the Persian Gulf. The 15 were released by Tehran last week after 13 days in Iranian detention. (New video shows Britons 'in comfort0')