"As has been clearly stated many times, no step-by-step plan is being considered," Khatibzadeh said on Saturday.
“The definitive policy of the Islamic Republic of Iran is the lifting of all US sanctions, whether those which Trump reimposed after withdrawing from the JCPOA or those which he initiated, as well as sanctions imposed under any other heading," he said.
"Obviously, this lifting of sanctions must be effective and must be verified by Iran," Khatibzadeh added.
His remarks came in response to claims made by US State Department deputy spokeswoman Jalina Porter about a planned meeting by representatives of Iran and other countries in Vienna Tuesday to discuss the troubled 2015 nuclear deal.
Restoring the nuclear agreement would be a major step, nearly three years after Trump scrapped it and imposed new sanctions or reimposed others lifted under the deal, forcing Iran to take a series of "remedial" measures in response to the decision.
Porter said Friday that the discussion would focus on “the nuclear steps that Iran would need to take in order to return to compliance with the terms of the JCPOA ”, using initials for what is formally known as the Joint Comprehensive Plan of Action.
In the talks, American officials would be down the hall while British, German, French, Chinese and Russian officials meet with Iran.
And that would be joined with discussion of “the sanctions relief steps that the United States would need to take in order to return to compliance, as well,” Porter said, an acknowledgment that the United States is currently in violation of the accord.
Khatibzadeh stressed that "the suspension of Iran's remedial measures and their reversal will take place only after the lifting of all sanctions and its verification" by the Islamic Republic.
In a tweet on Friday, Iran's Foreign Minister Mohammad Javad Zarif said the aim of the Vienna session would be to “rapidly finalise sanction-lifting & nuclear measures for choreographed removal of all sanctions, followed by Iran ceasing remedial measures".
"No Iran-US meeting. Unnecessary,” he added Friday.
American officials have said they were willing to meet directly with the Iranians, but the Iranian government has insisted on working through the Europeans, a stance which Deputy Foreign Minister Abbas Araqchi reiterated Friday.
“We only negotiate with the members of the JCPOA. The parties that are now known as the P4+1 will be our negotiating partners. They can talk to the other sides as they wish. We have no direct or indirect dialogue with the Americans,” he said.