"We cannot allow ourselves to be bullied by the Russians out of ratifying this agreement," said US Senator Joe Lieberman, whose name has been mentioned among the possible vice presidential candidates for the Republican Party.

Lieberman and Senator Lindsey Graham stopped in Warsaw after a trip to the Georgian capital of Tbilisi, where they met President Mikheil Saakashvili and visited displaced Georgians.

Lieberman said they were on a "mission of solidarity" with Georgia and the region. Russia should be held accountable for its invasion and Georgia should get the "military ability to defend themselves" and prevent future attacks, he told reporters.

Lieberman said "serious consideration" should also be given to stripping Russia of the 2014 Olympics.

Both senators are on the chamber's armed services committee. Graham is a Republican and Lieberman an independent who was the Democratic vice presidential nominee in the 2000 election.

Their trip to Poland came a day after Polish Foreign Minister Radek Sikorski signed a deal with US Secretary of State Condoleezza Rice to host 10 US missile interceptors on Polish soil in return for a pledge of American military aid, including Patriot air defence missiles.

Russia has fiercely opposed the planned shield, despite repeated US assurances that it's meant for defence against missile threats from "rogue states" like Iran, not target Moscow's strategic nuclear arsenal.

Graham said the system has "nothing to do" with Russia's nuclear arsenal, and that Russia was "manufacturing" the threat.

"You have chosen wisely," he said of Poland's agreement to host the US missile shield. "I hope it will be ratified by your parliament quickly." (dpa)