Warsaw and Washington signed a deal Wednesday to deploy a US missile shield in Poland, in the face of deep anger and threats of retaliation from Moscow.

"This will help us to deal with the new threats of the 21st century, of long-range missile threats from countries like Iran or from North Korea," said US Secretary of State Condoleezza Rice shortly before inking the accord with Poland's Foreign Minister Radoslaw Sikorski.

The signing came amid heightened tensions between the United States and NATO, on the one hand, and Moscow on the other over Russia's conflict with pro-Western Georgia.

Rice sought to fend off the criticism saying: "Missile defence of course is aimed at no one. It is in our defence that we do this."

Later she told reporters: "It is not aimed in any way at Russia."

The United States plans to base 10 interceptor missiles in Poland -- plus a radar facility in the neighbouring Czech Republic -- between 2011 and 2013.

"I consider this (development) positive... It doesn't surprise me," Czech President Mirek Topolanek told journalists in Prague after a cabinet meeting as he welcomed the signing of the agreement in Warsaw.

Both former Soviet Bloc nations have been NATO members since 1999, and the missile shield will complete a system already in place in the United States, Greenland and Britain.

Russia rejects US arguments that the shield -- endorsed by all 26 NATO member states earlier this year -- is meant to fend off potential missile attacks by what Washington calls "rogue states".

Polish President Lech Kaczynski said the deal it was a sign of the crucial "strategic alliance" of Western nations.

"We have to remember that Western ... countries have certain values and principles in common," he said. "We have to stand up for these principles and we have to defend them."

Moscow views the shield as a security threat designed to undermine Russia's nuclear deterrent.

"We will be forced to respond to this adequately. The EU and US have been warned," Russian President Dmitry Medvedev said last month as the long-running missile talks moved to a close.

Last week the deputy head of Russia's General Staff, Anatoly Nogovitsyn, warned Poland was making itself a target "100 percent" by participating in the US programme.

Kaczynski hit back in a televised address Tuesday, saying: "Our neighbours should now understand that our nation will never give in, nor allow itself to be intimidated".

Both Warsaw and Prague have had rocky relations with Moscow since they broke free from the crumbling communist bloc in 1989, and ties have worsened since they joined NATO and then in 2004 the European Union.

US and Polish negotiators signed a preliminary deal in Warsaw last Thursday after 15 months of negotiations.

With Western relations with Moscow at their lowest ebb in years because of the Georgia conflict, there have been suggestions that the timing of the missile deal was no accident.

"Obviously, there is a certain environment you are operating in. You can't deny it," US negotiator John Rood said.

Rice said: "It is a difficult time but I think we shouldn't overstate the depth of the difficulties... The Cold War is over."

To calm Moscow's ire, Poland has offered to allow Russian inspections of the missile facilities.

Negotiations saw the United States accept Poland's demands for extra security guarantees to offset the potential risks of hosting the shield, including a Patriot missile air-defence system and greater military ties.

The missile plan foresees the deployment of several hundred US troops in Poland to service the shield facility and the Patriot missiles, which will gradually be turned over to the Poles once they have been trained to use them.

Washington and Prague sealed the radar deal in July, but both accords must still be ratified by Polish and Czech parliaments.