Mosbacher gave her first public address in Poland since taking over the role of US ambassador while at a Warsaw event promoting a book about her predecessors.
She said Poland was developing dynamically and that she wanted to grow trade ties, specifically mentioning US supply of liquefied natural gas to Poland, which would also address the matter of Polands energy security.
Poland last year accepted its first shipment of American LNG, and later signed a deal for the long-term supply of the gas from the US, as it vies to diversify supplies, reduce its dependence on Russia, and establish itself as a regional energy hub.
Mosbacher also said she wanted to see further Polish-US military partnership, highlighting that the US had sent 6,000 troops to Poland and its neighbouring countries since Russias 2014 annexation of Ukraines Crimean peninsula.
Mosbacher took over as US ambassador last week.
According to Polish Radio, she is expected to take part in a meeting between the Polish and US presidents at the White House next Tuesday. (vb)