MOSCOW—An international firestorm erupted over the possibility that a Russian official could become the new president of global police agency Interpol, as Moscow denounced a demand by U.S. senators that the Trump administration block the candidacy of a Kremlin-backed nominee.

Interpol confirmed Tuesday that Maj. Gen. Alexander Prokopchuk a veteran Russian Interior Ministry official, had been nominated for president, amid allegations that Moscow has used the international police agency to go after political foes.

A bipartisan group of U.S. senators, including Florida Republican Marco Rubio and Chris Coons (D. Del.), issued a joint statement Monday, accusing Russia of routinely abusing Interpol “for the purpose of settling scores and harassing political opponents, dissidents and journalists.”

Electing Mr. Prokopchuk as president, would be “akin to putting a fox in charge of a henhouse,” the senators said in the statement.

The Kremlin was quick to fire back, charging that the senators’ intervention was tantamount to “a kind of election interference, the election held by this international organization,” presidential spokesman Dmitry Peskov said during a conference call with reporters Tuesday.