If Trump attempts to loosen sanctions against Russia for its involvement in the conflict in eastern Ukraine or its interference in the 2016 U.S. election, Congress could defy him by pursuing even stronger penalties. And if he offers platitudes for Putin without addressing Russia’s election meddling, it will renew questions about whether Trump accepts the findings of his own intelligence officials that Russia intended to disrupt the democratic process on his behalf.

“The president is boxed in,” said Nicholas Burns, a former U.S. ambassador to NATO under President George W. Bush. “Why would you give Putin any kind of concession at the first meeting? What has he done to deserve that?”

He added, “If you try to curry favor offer concessions, pull back on the pressure, he’ll take advantage. He’ll see weakness in a vacuum.”