(CNN) -- Authorities have officially dropped all charges against an American who tried to snatch back his children from his ex-wife in Japan, the Fukuoka prosecutor's office said Thursday.

Charges had been technically "on hold" since Christopher Savoie was released from jail in October, though legal experts had said the move essentially meant the charges had already been dropped.

The prosecutor's office said at the time that Savoie was released after he promised not to take his children back to the United States "in this manner."

It was not clear whether he had a chance to see his children after his release.

Savoie, 38, a Tennessee native and naturalized Japanese citizen, allegedly abducted his children -- 8-year-old Isaac and 6-year-old Rebecca -- as his ex-wife walked them to school on September 28 in Yanagawa.

With the children, Savoie headed for the nearest U.S. consulate in Fukuoka to try to obtain passports for them. Screaming at guards to let him in the compound, Savoie was steps from the front gate but still standing on Japanese soil when he was arrested.

Savoie and his first wife, Noriko Savoie, were married for 14 years before a bitter divorce in January. The couple had lived in Japan, but moved to the United States before the divorce.

Noriko Savoie received custody of the children and agreed to remain in the United States. Christopher Savoie had visitation rights.

On the day that the children were to start school in August, Savoie learned that his ex-wife had fled with them to Japan.

Savoie later filed for and received full custody of the children, and police in Franklin, Tennessee, issued an arrest warrant for his ex-wife.

But Japan is not a party to the 1980 Hague convention on international child abduction -- though the government has expressed interest in reconsidering -- so the warrant was not recognized by Tokyo.

Japanese law follows a tradition of sole-custody divorces. When a couple splits, one parent typically makes a complete and lifelong break from the children.

Complicating the matter is the fact that the couple is still considered married in Japan, because they never divorced there, police said. The children also hold Japanese passports, Japanese authorities have said.

Foreign parents have had little luck in regaining custody, the U.S. State Department said.

Savoie's current wife, Amy, said in October that her family has been ripped apart.

"Isaac and Rebecca had a very, very happy situation here in Tennessee," she said. "They have people who love them here."

She said she did not think the parties could work out an agreeable arrangement regarding the children.

"There are two parents who love these children and one of them has just been -- just cast aside."

CNN's Kyung Lah contributed to this report.