HONOLULU — The Hawaii state employee who mistakenly sent an alert warning of a ballistic missile attack has refused to cooperate with federal and state investigators, officials said Thursday.

Lisa Fowlkes, head of the Federal Communications Commission Public Safety and Homeland Security Bureau, said the agency was disappointed by the refusal.

“We hope that person will reconsider,” she told members of a U.S. Senate commerce committee in Washington during a hearing on the alert that caused widespread panic and confusion.

However, Fowlkes said she was pleased with the cooperation of leaders of the Hawaii Emergency Management Agency.

Meanwhile, U.S. Sen. Brian Schatz, a Democrat from Hawaii, told the committee he was introducing legislation making it clear that the authority to issue missile alerts rests with the U.S. departments of Defense and Homeland Security, not with state and local governments.

“It is increasingly clear to me that if we get all 50 states and all the territories and 3,007 counties across the country participating in this program, the likelihood of another mistaken missile alert as a result of human or bureaucratic error is not zero,” Schatz said. Spokesman Richard Rapoza said the Hawaii Emergency Management Agency has encouraged employees to cooperate with investigations of the error.