Warsaw  - Polish Prime Minister Donald Tusk and President Lech Kaczynski met Wednesday to discuss the proposed US anti-missile defence shield on Polish soil amid reports of a standstill in talks between Washington and Warsaw, and of the US turning to Lithuania.

Tusk said the US had "absolutely not" abandoned talks with Poland. The negotiations are taken seriously by both sides, he said, and there were no "last chance" meetings in the complicated process.

Tusk also hoped the talks would convince Kaczynski that making tough demands was in Poland's interests.

Polish media reports said Kaczynski was worried Tusk's stance may damage Polish-US relations, and had argued for signing the American offer as it stands - while Tusk saw the US as beginning to understand Poland's motivation, with an agreement possible even in two weeks.

Tusk also met with Foreign Minister Radek Sikorski earlier Wednesday, shortly after Sikorski's return from a meeting with US Secretary of State Condoleezza Rice.

Poland has been negotiating hard for military aid in exchange for the US hosting rights - but Russia suspects the missile shield could be used against it despite US assurances it is meant for "rogue states" like Iran.

Moscow Tuesday warned it undertake a "military-technical" response if the plan goes ahead.

Polish presidential aide Michal Kaminski called the Russian comments "unacceptable" and said it was unfortunate that politicians the other side of Poland's eastern border were still using the language of "imperial ambition."

It was unacceptable to threaten military action when the missile shield by nature was for defence purposes, he said. Moscow's comment was further proof Poland needed to strengthen its own security and alliance with the US. (dpa)