Polish Foreign Minister Radoslaw Sikorski has warned that sanctions against Russia - a measure Warsaw supports in retaliation for the annexation of Crimea - are better used as a threat than actually imposed.
Poland, which shares a border with Ukraine and Russia's Kaliningrad enclave and is a member of the European Union and NATO, has supported action against Moscow, including visa bans and asset freezes on people close to President Vladimir Putin.
"Sanctions are like nuclear weapons - it is better to use them as a threat than to deploy them," Sikorski told the mass-circulation German daily Bild.
"But in the current situation we have no choice. We have to weigh up the sanctions and how they will affect us. On the other hand, doing nothing may be costlier in the long term."
Europe is especially worried that Russia may restrict its exports of oil and gas, on which countries like Germany rely.
Russia's annexation of Ukraine's Crimea peninsula has made some NATO members in former communist central and eastern Europe such as Poland anxious about their own security, prompting the United States to reassure them that it will protect them if needed, in line with NATO security guarantees.
(Reporting by Stephen Brown; Editing by Tom Heneghan)