WARSAW, Poland (AP) — President Joe Biden has tried to reassure Poland that the United States would defend against any attacks by Russia. And he’s acknowledged that the NATO ally has borne the burden of the refugee crisis from the war in neighboring Ukraine. “Your freedom is ours,” Biden told Poland’s president, Andrzej Duda, echoing of one of Poland’s unofficial mottos. At the Presidential Palace in Warsaw, the two leaders spoke of their mutual respect and shared goals to end the Russian invasion of Ukraine. Biden also called the “collective defense” agreement of NATO a “sacred commitment,” and said that the unity of the Western military alliance was of the utmost importance.