WARSAW, Jan. 27 (Xinhua) -- Visiting U.S. Secretary of State Rex Tillerson discussed here Saturday security issues with Polish Prime Minister Mateusz Morawiecki, with NATO strengthening and Nord Stream 2 gas pipeline among the main issues raised during the meeting.

"Poland is a very strong ally", said Tillerson during a press conference after the meeting. He also congratulated the country on having already fulfilled a commitment of spending up to 2 percent GDP expenditure on defense.

"Poland and the United States together are against Nord Stream 2 gas pipeline, which undermines the overall security and energy stability of Europe", Tillerson said. He expressed hope that the U.S. and Poland could make closer cooperation in the field of energy.

The Nord Stream 2 pipeline is set to run from the Russian coast along the Baltic Sea bed to the German shore, and is scheduled to be put into operation by the end of 2019. The total capacity of two strings of Nord Stream 2 is 55 billion cubic meters of gas per year.

At the press conference, Poland's Foreign Minister Jacek Czaputowicz, who also took part in the meeting, said that "Mr. Tillerson's visit is for us a confirmation of close ties between Poland and the United States, ... a confirmation of the U.S. interest in the Central and Eastern Europe region".

"We have common, convergent views on the need to strengthen NATO", Czaputowicz added. He expressed the hope that the military contracts between the two countries can be signed very soon.

On Saturday, the U.S. Secretary of State also took part in commemorations of the 73rd anniversary of the liberation of the Nazi concentration camp Auschwitz -Birkenau by the Monument to the Ghetto Heroes in Warsaw.

Tillerson called it "a place of unimaginable monstrosities and tragedies" and emphasized that "we can never remain indifferent to evil".

Tillerson arrived here for a two-day visit to Poland following his participation in the World Economic Forum in Davos, Switzerland. On Friday evening, he also met with Polish President Andrzej Duda.

Duda's aide Krzysztof Szczerski said on Friday that the two "agreed on a Polish-US activity roadmap for the near future regarding ... economic and political relations and international security".

On Saturday, Tillerson is also supposed to meet with Jaroslaw Kaczynski, the leader of Poland's ruling party, Law and Justice (PiS).