British Foreign Secretary Jeremy Hunt said Tuesday that he met with the family of jailed Nazanin Zaghari-Ratcliffe during his visit to Iran.
"No child should have to go this long without their mother," Hunt wrote on Twitter alongside photos of him with Zaghari-Ratcliffe's four-year-old daughter Gabriella.
He also met her mother and brother during his brief visit to Tehran on Monday, and pressed for her release during his meeting with Foreign Minister Mohammad Javad Zarif.
"British-Iranian dual nationals wrongly imprisoned must be freed," Hunt tweeted later on Monday.
"I've pressed hard on this today - innocent people should not be turned into diplomatic pawns."
Zaghari-Ratcliffe, who works for the Thomson Reuters Foundation - the media organization's philanthropic arm - was arrested at Tehran airport in April 2016.
She is serving a five-year jail sentence for sedition - and has denied all charges filed against her.