UPDATE - UK premier condemns Iran's execution of British-Iranian national

ADDS CONDEMNATION BY GERMANY; REVISES DECK

By Aysu Bicer and Beyza Binnur Donmez

LONDON / ISTANBUL (AA) – British Prime Minister Rishi Sunak on Saturday called Iran's execution of a British-Iranian national a "cowardly act," denouncing what he called a killing "by a barbaric regime with no respect for the human rights of their own people."

Earlier on Saturday, Iran announced the execution of Alireza Akbari, a former deputy defense minister, days after he was sentenced to death on charges of spying for Britain.

"I am appalled by the execution of British-Iranian citizen Alireza Akbari in Iran. My thoughts are with Alireza's friends and family," Sunak said on Twitter.

Foreign Secretary James Cleverly also issued a statement following the execution, saying it would not go "unchallenged."

"This barbaric act deserves condemnation in the strongest possible terms. Through this politically motivated act, the Iranian regime has once again shown its callous disregard for human life.

"We will be summoning the Iranian Charge d'Affaires to make clear our disgust at Iran's actions. Our thoughts are with Akbari's family," he said, shortly before the top Iranian diplomat in Britain was in fact summoned.

According to Iran's Mizan News Agency, Akbari was executed on charges of corruption and "extensive acts against the country's internal and external security."

- Germany calls execution 'another inhumane act' by Iran

The German Foreign Office expressed solidarity with the UK, calling the execution "another inhumane act" by Tehran.

"The execution of Alireza Akbari is yet another inhumane act by the Iranian regime," the office said on Twitter. "We stand with our British friends and will continue to closely coordinate our measures vis-a-vis the regime and our support for Iran's people."