"What we want is civil nuclear technology," Khatami said, explaining that Iran still intends to enrich uranium "at 3.5 percent as fuel destined for nuclear plants."
"Iran will never give up this program," he said.
On Tuesday, Iran pledged to suspend uranium enrichment for an indefinite period under a deal with France, Germany and Britain, whose foreign ministers traveled to Tehran to defuse a nuclear crisis.
Iran has fiercely denied accusations by the United States that it is hiding a nuclear weapons program behind its civilian industry, but weapons-grade uranium would be significantly more highly enriched than that used for fuel.
Earlier Wednesday, Khatami said "we have agreed to suspend enriching uranium temporarily. We will not give gas to the devices that need gas for the time we see beneficial.
"In other words we will stop ... in order to show our goodwill and show our program is on a peaceful track."
But he said the decision on the length of time that enrichment is suspended is "100 percent in our hands".
Several Iranian officials insisted that this decision was "voluntary," and that Iran reserved the right to resume enrichment if it is deemed to be in the country's best interest.
Iran is building a 1,000 megawatt nuclear power plant with Russia's help in Bushehr, in the south of the country, and aims to construct six other plants with the same capacity by 2020.
Tehran has yet to fix a date to sign an additional protocol to the Non-Proliferation Treaty (NPT) that allows for tougher UN inspections of its nuclear program.
"We are discussing it. I cannot give you the exact date," the president told reporters when asked when Iran would sign the text. He said that after Iran signs the accord, it would have to be submitted to parliament for approval.