Poland and the United States may sign an agreement within the week on installing a U.S. anti-missile base in Poland, a senior Polish official said on Sunday.
"The negotiations are winding down and everything points to an agreement being signed this week," PAP news agency reported Zbigniew Chlebowski as saying, the Reuters reported.
Chlebowski, head of the ruling Civic Platform party's parliamentary caucus and mouthpiece for Prime Minister Donald Tusk, declined to give details.
But speaking on a public-affairs radio show earlier on Sunday, Chlebowski criticized presidential aide and former foreign minister Anna Fotyga for paying an unannounced visit to Washington at the end of the negotiating process.
"Whenever talks are in their final phase, only negotiators should take part in them, and Madam Minister Fotyga is not one of them," he said.
His criticism reflected rivalry over foreign policy between the liberal government and conservative President Lech Kaczynski.
Fotyga on Sunday defended her U.S. visit whose purpose she said had been "to sound out the other side's intentions."
"That mission has been accomplished. I am convinced the Bush administration wants to bring the matter to its successful conclusion," she said on news channel TVN24.
Washington wants to install 10 land-based interceptors in Poland as part of an anti-missile shield designed to protect the United States and its NATO allies from attack by what it calls "rogue states", particularly Iran.
Agreement has been reached with the Czech Republic which is to host the shield's radar installation.
Talks with Warsaw have frequently stalled over the Poles' insistence on massive U.S. military aid including short- and medium-range air defences such as Patriot PAC-3, THAAD or AMRAAM missiles.
Russia sees the proposed system as a threat to its national security and has warned of a new arms race if is deployed.