Poland 'agrees' to host US shield
The US wants to install interceptor missiles in Poland and a radar base in the Czech Republic.
Russia opposes the project, saying it would destabilise global security and undermine its own nuclear deterrent.
In October, Russian President Vladimir Putin compared the plans to the Cuban missile crisis of the 1960s, which saw the US and Soviet Union go to the brink of nuclear war.
Russia has threatened to point missiles at Europe if the US positions elements of the new missile shield near its borders.