Poland's deputy prime minister is exploring reducing the country's dependence on Russian natural-gas imports by buying liquified gas from the United States.

In a visit to the United States this week, Mateusz Morawiecki, who is also Poland's minister of economic development, met with U.S. Energy Secretary RIck Perry to discuss purchasing U.S. gas and got a "very positive response," he told reporters.

Morawiecki told Reuters on April 5 that he reached an "understanding" with Perry to work toward a deal.

Poland, a NATO member, currently gets about two-thirds of its gas from Russia, and has been striving to find alternative sources for national security reasons.

The purchase of gas from the United States would diversify Poland's energy supplies and increase its energy security, Morawiecki said.

"I am very much concerned. I think that what Russia is doing since invading Georgia in 2008 and Ukraine in 2014, it is clearly against international public law," he told Reuters.

"We strongly oppose this expansionary and aggressive policy by Russia. Cyberthreats to the Baltic States and Poland are difficult to overestimate. I believe this is a real threat," he said.

Poland has a liquefied-natural-gas terminal in the Baltic Sea that opened last year. Morawiecki said U.S. gas from Texas is currently more expensive than liquified gas the country could import from Algeria or Qatar, but he believes a lower price can be negotiated with U.S. suppliers.

A fracking revolution in the past decade turned the United States into a natural-gas superpower, rivaling Russia and other major suppliers around the world. The United States started exporting some of its abundant gas only a year ago and has not as yet sent any to Northern Europe.

Poland's contract to buy gas from Russia's state-owned Gazprom expires in 2022.

With reporting by Reuters, Polskieradio.pl, and Dziennik.pl