Iranian president Hassan Rouhani on Thursday ordered to proceed the country's missile programme "with high speed and seriously" and expand Iran's missile capabilities, in response to the US considered sanctions, state media reported.
Rouhani's remarks followed the US Treasury Department's recent announcement that it was considering sanctions against a number of Iranian and international individuals and agencies for their alleged involvement in developing Iran's ballistic missile programme, official IRNA news agency reported.
In a letter to the defence minister, Rouhani said "it is necessary to follow, more seriously and with high speed, the production of different kinds of missiles within the framework of the defensive policies".
The Defence Ministry was obliged to expand the missile capabilities of Iran, in case the US insists on its "false and interfering measures", Rouhani said.
During the past nuclear talks, Iran emphasized that it will never negotiate over its deterrent power, including its missile programme, and will never accept any restrictions in this regard.
The new US move to add individuals and companies to the sanction list was a response to Iran's recent test of a ballistic missile.
In October, Iran announced the tests of long-range Emad missile which could be guided and controlled until hitting the target with high precision.
A UN experts' report in December said that Iran violated UN Security Council Resolution 1929 by test-firing the Emad missile which is capable of delivering a nuclear warhead.
The UN report said the Emad ballistic missile has a range of "no less than 1,000 km with a payload of at least 1,000 kg".
Under Resolution 1929, Iran was prohibited from working on ballistic missiles capable of delivering nuclear warheads.