Iran toughened Thursday its criticism of Turkey over its plan to host an early-warning radar as part of NATO's missile defence system, saying it will create tension and lead to "complicated consequences."

"We expect friendly countries and neighbours ... not to promote policies that create tension, which will definitely have complicated consequences," foreign ministry spokesman Ramin Mehmanparast said in remarks carried by the state television website.

"We believe that the installation of some parts of the NATO missile system in Turkey will not help the security and stability of the region at all, nor that of the host country," Mehmanparast said.

Iran "condemns any action that creates an arms race in the world and region," he added.

On Monday, Tehran criticised Ankara in a more subtle tone, with a deputy foreign minister saying the missile shield radar would not "improve security in the region."

"Iran and Turkey are two friendly neighbouring nations ... and have the ability to fully preserve their own security without any foreign intervention," said Hassan Ghashghavi, deputy minister for consular affairs.

The remarks came after Ankara announced that technical negotiations on the deployment of the radar had "reached a final stage."

"It is foreseen that the early warning radar system dedicated by the United States to NATO will be deployed in our country," Selcuk Unal, spokesman for the Turkish foreign ministry, said on Friday.

Leaders of the 28-member NATO alliance gave their backing last year for the Europe-wide ballistic missile shield -- which US officials say is aimed at thwarting missile threats from the Middle East, particularly Iran.

Since Monday, there has been a growing chorus of military officials and lawmakers criticising Turkey. This is a rarity, as Tehran has made maintaining good relations with Ankara a priority in recent years, and has considered Turkey an ally for its refusal to implement Western sanctions against Tehran over its controversial nuclear programme.

Iranian leaders have also publicly applauded Turkey for its falling out with Tehran's regional arch-foe Israel.

"American and Western presence in Muslim countries is troublesome and harmful to these countries," said Defence Minister Ahmad Vahidi.

"The West ... should be aware that we will not tolerate any aggression against our national interests by any country," he added.

Esmaeel Kosari, influential lawmaker and member of the foreign policy committee, on Wednesday accused Turkey of adopting an "ambiguous dual approach" in its recent decisions.

"While Turkey's past stances used to raise hope amongst Muslim nations, its recent decisions are giving rise to doubt and uncertainty," Kosari was quoted as saying by Fars news agency.

"Regional nations cannot tolerate contradictions in Turkey's behaviour," he said, while advising Ankara to reconsider its decision on the missile shield.

Another top lawmaker, Mohammad Dehghani, who sits on parliament's presiding board, said the decision to host NATO radars showed Turkey's "naivete" and its "behind-the-scenes collusion" with the West.

He also regretted Turkey's recent decision to toughen its stance on the popular revolt in Syria being repressed by President Bashar al-Assad -- Iran's main regional ally.

"Turkey has recently joined efforts by America and the Zionist regime in delivering a blow to the resistance front in Syria," Dehghani said.