“The United States knows too well the cost of terrorism directed at our own diplomats around the world, and our hearts go out to the Iranian people after this violent and unjustifiable attack claimed the life of at least one of their diplomats,” Secretary of State John F. Kerry said in a statement.

An al Qaeda-linked group based in Lebanon claimed responsibility for explosions that killed at least 23 people and wounded more than 140.

The attack in Beirut may add either a layer of complexity or help along the high-stakes international talks over Iran’s nuclear program slated to reopen in Geneva on Wednesday.

“I think from the side of the West, this was a way to show consistency and sympathy to the Iranians when they’ve been targeted by al Qaeda,” said Trita Parsi, who heads the National Iranian American Council. “It’s a way for the U.S. to repeat their claim or assertion that the U.S. is against terrorism, no matter who it targets.”