BRUSSELS: The head of NATO called Friday for the U.S., Russia and NATO to link their missile defense systems against potential new nuclear threats from Asia and the Middle East, saying that the old foes must forget their lingering Cold War animosity.

Secretary-General Anders Fogh Rasmussen appealed for unity a day after the U.S. shelved a Bush-era plan for an Eastern European missile defense shield that has been a major irritant in relations with Russia.

"We should explore the potential for linking the US, NATO and Russia missile defense systems at an appropriate time," Fogh Rasmussen said. "Both NATO and Russia have a wealth of experience in missile defense. We should now work to combine this experience to our mutual benefit."

Fogh Rasmussen said in a speech calling for a rethink of NATO-Russia relations that long-range ballistic missile technology in the hands of such countries as North Korea and Iran threatens the West and Russia in large part because it could lead to regional proliferation.

"If North Korea stays nuclear, and if Iran becomes nuclear, some of their neighbors might feel compelled to follow their example," he said. "The proliferation of ballistic missile technology is of concern not just to NATO nations, but to Russia too."

Fogh Rasmussen said NATO and Moscow have failed to jointly take on global security threats including terrorism.

"When the Cold War ended 20 years ago, NATO and Russia developed rather unrealistic expectations about each other," he said. "Those flawed expectations ... continue to burden our relationship."

He did not elaborate on how or to what extent the Russian, NATO and American anti-missile systems could be linked up.

The U.S. said the decision to abandon the Bush administration's plans came about because of a change in the U.S. perception of the threat posed by Iran. U.S. intelligence decided short- and medium-range missiles from Iran now pose a greater near-term threat than the intercontinental ballistic missiles the Bush plan addressed.

A new missile-defense plan would rely on a network of sensors and interceptor missiles based at sea, on land and in the air as a bulwark against Iranian short- and medium-range missiles.

Russian Prime Minister Vladimir Putin on Friday praised Obama's decision and urged the U.S. to also cancel Cold War-era restrictions on trade with Russia.

Russian leaders had threatened to deploy short-range missiles to the Baltic exclave of Kaliningrad near Poland if the U.S. moved ahead with the missile defense plan.

On Friday, the Interfax news quoted an unnamed Russian military-diplomatic source as saying that such retaliatory measures would now be frozen and, possibly, fully canceled in response to Obama's decision to scrap the missile defense shield.

In the past, Russia has said it is ready to jointly work on missile defense with the NATO and the United States.

But it views Iran being far from obtaining a long-range missile technology and says it's necessary to jointly analyze missile threats from that country and other nations before taking any further action.

In 2007, Putin who still was Russia's president at the time, offered the U.S. to use a Soviet-era radar in Azerbaijan as an alternative to the Bush administration's missile defense plan for Eastern Europe. The Bush administration said the facility couldn't replace the planned missile shield.

The NATO allies have done some technical work with the Russians on missile defense in the past. But this has slowed down in recent years as the relationship tanked over NATO enlargement and the Georgian war. Fogh Rasmussen's speech is a bid to revive such joint work.

Turkey's military said Friday that it was planning to spend $1 billion (euro680 million) on four long-range missile defense systems but denied it was buying missile interceptors for use against Iran.