Ahmadinejad 'under pressure'
The resolution was the first against Iran in almost four years.
Alireza Ronaghi, Al Jazeera's correspondent in Tehran, said: "Ahmadinejad has been under a lot of pressure and this is the reaction we should have expected from him.
"Iran has the capacity to enrich uranium from 3.5 to 5 per cent. It's obvious that if they connect a few more cascades of centrifuge machines - which are responsible for enriching uranium - they could definitely reach the capacity of 20 per cent.
"But if they cross the line of five per cent, it will worry the IAEA and the permanent members of the UN Security Council that Iran can reach much higher levels classified as 'weapons-grade' material."
The Iranian vice-president responded on Monday by ordering the construction of 10 new nuclear plants.
Ali Akbar Salehi told state radio that Tehran had no plans to build any new uranium enrichment faciliities until the IAEA passed its resolution rebuking Iran.
"We had no intention of building many facilities like the Natanz site, but apparently the West doesn't want to understand Iran's peaceful message," The Associated Press news agency quoted Salehi as saying.
France called Iran's response to the IAEA "ridiculous" and "childish", and warned that such a stance could lead to the imposition of new UN sanctions.
Iranian MPs demanded that Ahmadinejad's government reduce co-operation with the IAEA in response to the resolution.
Israel, ambiguous over its own possible nuclear arsenal and unlike Iran, not a signatory of the nuclear non-proliferation treaty, has said a nuclear-armed Iran would be a threat to its existence.
Ahmadinejad said in his speech that Israel could not do a "damn thing" to stop his country's nuclear programme, which the West suspects is a front to build bombs.
"The Zionist regime [Israel] and its [western] backers cannot do a damn thing to stop Iran's nuclear work," he said.