The U.K. government has decided to provide diplomatic protection to a British-Iranian woman detained in Iran for nearly three years.

The Foreign Office said Friday the move means Britain formally asserts that Iran has failed to meet its international obligations in its treatment of Nazanin Zaghari-Ratcliffe.

Zaghari-Ratcliffe was arrested in April 2016 on charges of plotting against the Iranian government. Her family denies the allegations.

Her husband Richard Ratcliffe welcomed the move Friday, saying it could lead to a resolution of her case within months.

"It changes the status for Nazanin's case," Ratcliffe told BBC radio. "Now it's also the British government's case and all the injustices that happen to Nazanin are effectively injustices against the British government."

He said the top priority is to have a doctor see Zaghari-Ratcliffe to provide urgent medical care.

"A couple of months ago she went on hunger strike because she wasn't getting any treatment, and was promised it but it didn't happen, so she got very low again recently. I'm sure this will give her a big lift," he said.

Foreign Secretary Jeremy Hunt said legal proceedings against Zaghari-Ratcliffe in Iran were deficient and that she has been denied proper access to health professionals.

"My decision is an important diplomatic step which signals to Tehran that its behavior is totally wrong," he said.

Hunt conceded the move is unlikely to lead to immediate results. The British government has long been seeking her release.