Vermont Sen. Bernie Sanders said Friday that he would vote for presumptive Democratic nominee Hillary Clinton in November, but declined to endorse her for now, saying he is waiting until she says what he wants to hear on a number of issues.

Mr. Sanders’s back-to-back television interviews underscored the position he and Mrs. Clinton are in as they negotiate about the Democratic Party’s platform. She wants him to get behind her campaign and help move his supporters to her corner. He wants her to move closer to his positions...