One of the major listening posts thought to be required for the shield to be operational is the Thule radar station on Danish-controlled Greenland, a Cold-War era US base that would require substantial modernisation.

"The United States has not asked us to use the Thule radar station in their missile defence project," said Danish Foreign Minister Per Stig Moeller, reacting to the report in the Jyllands-Posten newspaper.

"And if such a request were made, the government would want a thorough political debate on the issue, in Denmark and in Greenland," he added.

"The government has informed the United States that it would be ready to study and consider a request if such a request were ever made," Moeller said.

Danish participation in the project -- designed to protect the United States from missile attack launched by so-called "rogue states" -- is seen as crucial.

The line of the current and former Danish administrations has always been that Denmark will only agree a policy on the US plans in the event of a formal US request for it to play a role.

The conservative-liberal coalition government plans to approach US officials on the issue at a NATO summit in Prague later this month, the report added, quoting parliamentary sources. Moeller confirmed that the suject was on the summit agenda.

"One of the main themes at the NATO summit in Prague will be establishing how to tackle the new threat of the spread of missiles and weapons of mass destruction, and missile defence will form an essential part of the talks," he said.

The head of Greenland's local government, Jonathan Motzfeldt, had been asked to attend the talks as part of the Danish delegation, he added.

Greenland residents are known generally to oppose the US plans amid concerns it will put their island at the centre of a new Cold war. Jyllands-Posten said the Danish government would present fuller details on plans for cooperation on the shield to a foreign policy committee next week.