Iran is still open to negotiations for reviving a nuclear deal with global powers but warned on Wednesday it would alter course if the West doesn't change its behaviour.
Foreign Minister Hossein Amir-Abdollahian made the comments on the sidelines of a visit to Oman, a Gulf state which played a mediating role in the build-up to the original 2015 agreement.
That deal between Tehran and global powers was designed to stop Iran from developing a nuclear bomb. Tehran has always denied such a goal.
Amir-Abdollahian's meeting in Muscat with Oman's Sultan Haitham bin Tareq came alongside stalled international talks to revive the 2015 pact.
Washington abandoned the deal in 2018 and reimposed crippling sanctions, prompting Iran to begin reneging on its own commitments.
On-off talks to revive the agreement began in April last year but Iran has now been hit with additional Western sanctions for its repression of nationwide anti-regime protests since September, and the supply of drones to Russia.
Washington said in early October that a return to the nuclear deal was unlikely in the near future.
"The window for reaching an agreement on the part of the Islamic Republic of Iran will not always be open," Amir-Abdollahian said in a video issued by Iranian state media.
"If the opposite parties do not stop hypocrisy, especially the Americans, and the Westerners do not act realistically, it is not certain that the window that is open today will remain open tomorrow," he said.
"If the Westerners want to continue their hypocritical and interventionist behaviour, we will move in the direction of another plan."
Iran blames foreign powers for stoking what it calls "riots" in its country.
The official Oman News Agency said the Iranian minister handed the sultan a letter from Iran's President Ebrahim Raisi, who visited Oman in May.
Without elaborating, ONA said the letter "deals with areas of cooperation between Oman and Iran in various fields".
Responding earlier to a question about a potential Omani mediation role in the stalled nuclear talks, the Iranian minister said "Omani authorities have always played a positive and constructive role in bringing the views of the parties closer" together.
US President Joe Biden has said that the nuclear deal was "dead," but he would not announce that publicly, according to a video that surfaced this month.