Iran’s top leader has said anyone who thinks negotiations are more important than building a missile system are traitors, his official website reports.
Ayatollah Ali Khamenei’s comments appear to be a response to a statement from a former president who said discussions were the way forward.
The statements come amid concern among world powers over a series of ballistic missile tests by Iran.
Iran denies the tests breach a UN resolution on its missile programme.
The resolution, passed last year, calls on Iran not to develop or test ballistic missiles capable of carrying nuclear weapons.
Iran test-fired a nuclear weapon-capable ballistic missile in October 2015 and carried out more ballistic missile tests earlier this month.
Iran’s missile programme was not banned under a deal last year with world powers which curbed its nuclear activity, but forms part of a resolution endorsing the agreement.
On Wednesday, UN Secretary General Ban Ki-moon said the recent missile test had caused “alarm and concern” but that it would be up to the United Nations Security Council to decide what to do, Reuters news agency reported.
In comments carried on his website, Ayatollah Khamenei said any negotiations should be backed by military strength.
“If the Islamic system pursues technology and negotiations without defence power, then this will be a retreat in the face of threats from other insignificant countries,” the website quoted him as saying.
“People say that tomorrow’s world is a world of negotiations and not a world of missiles. If they say this thoughtlessly, it shows that they are thoughtless. However, if this is intentional, then this is treachery.”
The statement comes days after former President Akbar Hashemi Rafsanjani tweeted “the future is in dialogue, not missiles”.
Mr Rafsanjani is close to the politically moderate President Hassan Rouhani, whose domestic position was enhanced by the success of the nuclear negotiations in getting sanctions lifted.