LONDON — The British government is being accused of concealing the failure of an unarmed ballistic missile launch ahead of a debate in Parliament over whether to refurbish the country’s aging Trident nuclear launching system.

Britain’s prime minister refused to say Sunday whether she knew about an unarmed Trident missile that reportedly failed when it was test-fired off the coast of Florida last year.

Theresa May told BBC she has total confidence in Britain’s Trident nuclear launching system, but didn’t confirm or deny a newspaper report about the alleged failure of a ballistic missile designed to carry nuclear warheads.

The prime minister was asked about the missile test after the Sunday Times reported that an unarmed missile launched from a submarine off Florida’s coast in June veered off course and may have headed toward the U.S.