Ukraine, which depends on American military aid for its survival, has long tried to maintain bipartisan support in the United States. That has never been easy, but it is getting harder, especially with the increased possibility that Donald J. Trump, no great friend of Ukraine, will return to the White House.

Ukraine’s president, Volodymyr Zelensky, is asked in nearly every interview what a second Trump administration would mean for Ukraine. While Mr. Zelensky chooses his words carefully, sometimes the emotional weight of the assumption behind the question — that Mr. Trump could end American military assistance, allowing Russia to succeed in destroying the Ukrainian state — spills into view.

Mr. Trump’s claim last week during his debate with Mr. Biden that he alone knew the path to peace is “a little scary,” the Ukrainian president said in an interview with Britain’s Channel 4 News.

“I’ve seen a lot, a lot of victims,” Mr. Zelensky said. “But that’s really making me a bit stressed.”

“If there are risks to Ukrainian independence, if we lose statehood — we want to be ready for this, we want to know,” Mr. Zelensky said in a subsequent interview last week with Bloomberg. “We want to understand whether in November we will have the powerful support of the U.S. or will be all alone.”