"This is a trade partnership. It has the ability to lift all of our countries," Kerry said on a visit to Poland.
He said the partnership "is really separate from any other issues that people may have on their minds," referring to allegations that US intelligence agencies spied on official communications of some EU states.
Kerry, speaking alongside his Polish counterpart Radoslaw Sikorski, also said US companies, with government support, would compete vigorously to win major defence contracts being put out to tender by Poland.
He added that the US military's plans for missile defence in Europe, in which Poland will play a part, were "absolutely on target."