“Compared to the March trip, Biden faces a heightened degree of trade-offs between domestic and foreign policy objectives,” said Richard Fontaine, the chief executive of the Center for a New American Security, a Washington research group. “His priority will be to increase pressure on Russia and aid to Ukraine, but to do so when the West is worried about oil and food prices, its remaining weapons stocks and a war that shows no end in sight.”

For now, Mr. Biden is under little political pressure at home to back away. Most of the debates about how much to turn up the heat on Mr. Putin, without provoking a major escalation in the war, takes place behind closed doors among his staff.

But there is concern that rising gas prices and the cost of keeping Ukraine armed and fed will begin to wear down enthusiasm, especially if Mr. Putin makes good on recent threats to limit gas supplies to Europe in the fall. Mr. Fontaine noted: “All the leaders he’ll meet are in the same general dilemma, and elections loom in the United States and elsewhere. Western unity is high, support for Ukraine still very solid and the desire to resist Russia real.”

But he also said that summit meetings “demonstrate how sustainable the various lines of effort will be as the war itself grinds away.”