WASHINGTON — President-elect Donald J. Trump said Friday that he was likely to abandon the American effort to support “moderate” opposition groups in Syria who are battling the government of President Bashar al-Assad, saying “we have no idea who these people are.”

In an interview with The Wall Street Journal that dealt largely with economic issues, including his willingness to retain parts of the Affordable Care Act, he repeated a position he took often during his campaign: that the United States should focus on defeating the Islamic State, and find common ground with the Syrians and their Russian backers.

“I’ve had an opposite view of many people regarding Syria,” Mr. Trump told The Journal. “My attitude was you’re fighting Syria, Syria is fighting ISIS, and you have to get rid of ISIS. Russia is now totally aligned with Syria, and now you have Iran, which is becoming powerful, because of us, is aligned with Syria.”

His comments suggest that once Mr. Trump begins overseeing both the public support for the opposition groups, and a far larger covert effort run by the Central Intelligence Agency, he may wind down or abandon the effort. But there are in fact two wars going on simultaneously in Syria.