Secretary of State Rex Tillerson is lashing out against Russia's plans to open a natural gas pipeline to supply energy to Germany, saying Saturday that it threatens stability in the region.

"Like Poland, the United States opposes the Nord Stream 2 pipeline," Tillerson said while at a joint press conference in Warsaw with Polish Foreign Minister Witold Waszczykowski.

"We see it as undermining Europe's overall energy security and stability," Tillerson continued. "Our opposition is driven by our mutual strategic interests."

Russia is a top supplier of natural gas to Europe, which the Trump administration is seeking to change by encouraging the export of U.S. natural gas exports into the European market now that the U.S. is a top producer of the fuel.

Russia's Nord Stream 2 natural gas pipeline that is still being constructed would supply Germany and other parts of Europe with the fuel, which is most commonly used for heating.

Poland, which has been a top U.S. supporter, recently penned a five-year contract to receive imports of natural gas from the U.S. However, Germany and the Czech Republic support the Russian pipeline as necessary to central Europe's economy benefits of the pipeline, even as the U.S. and Poland oppose it.

The Trump administration said increased reliance on Russian gas makes the region more dependent on a country known for using energy as a weapon and turning off the spigot to pressure Europe to get its way.

Meanwhile, the U.S. put in place new sanctions on Friday against Russia.

The sanctions came as a French-owned liquefied natural gas tanker carrying some amount of Russian natural gas was preparing to dock in Boston harbor Saturday. The tanker has been reported as demonstrating the hurdles in attempting to ban Russia energy products in a global commodity market where products, like oil and natural gas, often mix.

Massachusetts and the Northeast U.S. is one of the most energy-constrained areas of the country, especially when it comes to natural gas. It is quite literally at the very end of the nation's energy supply chain, and therefore subject to both market and physical constraints in getting supply there.

Even with the energy boom in the U.S. making natural gas both cheap and plentiful, the Northeast still suffers from price spikes and constraints when demand spikes, such as during the cold snap and bomb cyclone earlier this month.