DETROIT — General Motors reported a sharp drop in second-quarter profit on Tuesday, mostly as a result of its strategic shift away from some key international markets.

But as G.M., the nation’s biggest automaker, is cutting back its overseas operations, the company is facing tougher economic conditions in its core North American market.

That combination could put pressure on the company in the months ahead as it copes with declining sales at home while restructuring its global business units.

G.M. reported net income of $1.7 billion during the quarter that ended in June, which represented a 42 percent decline from the $2.9 billion it earned in the same period in 2016. Its adjusted earnings per share, however, rose about 6 percent to $1.89 and exceeded Wall Street estimates.