The deal, to increase annual Russian gas supplies to 10 billion cubic meters, will come into force after being signed by governments of the two states, Polish deputy economics minister Joanna Strzelec-Lobodzinska said.
Poland's PAP news agency reported that the text of the inter-government agreement has already been agreed upon.
Russian energy giant Gazprom and Poland's gas monopoly PGNiG are also to sign a contract on the issue.
Gazprom's Deputy CEO Alexander Medvedev said the contract would be finalized within two weeks.
The Russian industry and energy ministry confirmed that the talks took place, but said it would disclose all details of the deal later on Monday.
An estimated 65-70% of all natural gas consumed in Poland comes from Russia.
