Azmoun, who has been playing his football in Russia since 2013, scored 23 goals in 36 matches for Iran since making his senior debut in 2014.

"It was a great honor for me to play for the national team and I will be proud of myself all my life," said Azmoun on his Instagram account.

"Unfortunately, despite my interest and my heart's desire, I have decided to say goodbye to my country's national team. It is definitely the most painful decision for a 23-year-old player," he added.

"My mother's serious illness was just over, and I was happy. But, unfortunately, the insults neither me nor my teammates deserved aggravated her illness, which compels me to make this difficult choice. I choose my mother."

Iran were knocked out of the FIFA World Cup on Monday after only toughing out a 1-1 draw against reigning European champions Portugal in their final Group B game.