US Defence Secretary Robert Gates offered Russia an unprecedented level of cooperation in missile defence activities yesterday, but his hosts made clear they were still against a planned missile shield in Europe.

The US says it wants to station elements of its shield in Poland and the Czech Republic as protection from missile attacks by countries such as Iran or North Korea. But Russia says the project threatens its national security.

The dispute has badly strained relations between Moscow and Washington and prompted some officials to draw comparisons with the Cold War.

"The days of the Cold War are over and no one should seek a return to them," said Mr Gates, on a European tour to ease concerns over US missile defence plans. "We invite Russia to join our defensive endeavour as a partner."

On Sunday, a senior US official travelling with Mr Gates said the Pentagon intended to move forward on the missile shield plan, whatever the response from Russia.

The US wants to station 10 interceptor missiles in Poland and radar equipment in the Czech Republic, at a cost of $3.5 billion.

Mr Gates, former CIA director and career Soviet analyst at the US intelligence agency, met Russian President Vladimir Putin. Afterwards, Mr Putin spoke by telephone to US President George W. Bush.

A Russian official who briefed reporters said Mr Putin and Mr Gates had a "serious and principled" discussion but gave no indication Moscow would take the Pentagon up on its offers of missile defence cooperation.

Russian Defence Minister Anatoly Serdyukov reacted coolly after talks with Gates earlier yesterday. "The Russian position on this issue remains unchanged," he said.

"The strategic missile defence system is a serious destabilising factor which could have significant impact on regional and global security," Interfax quoted him as saying.