ISLAMABAD, Pakistan — An American diplomat involved in a fatal accident was allowed by the Pakistani authorities to leave the country on Monday just days after officials here prevented him from boarding a United States military plane, according to American officials.

“We can confirm that the American diplomat, who was involved in a tragic car accident on April 7 in Islamabad, has departed Pakistan,” Nolen Johnson, a State Department spokesman, said in an email.

Pakistani authorities made no comment about the sudden departure of the diplomat, who found himself at the center of the latest diplomatic dispute between the two countries. Local news media outlets reported the departure of the diplomat, citing anonymous official sources.

The diplomat, Col. Joseph Emanuel Hall, a military attaché at the United States Embassy in Islamabad, is accused of having run a red light and fatally hitting a 22-year-old man on April 7. Another passenger on the bike was injured.