'I am a son of Iran': Azmoun backs his nation at World Cup despite missing out on squad
Azmoun, who is his country's second-leading scorer of all time, was left out of coach Amir Ghalenoei's preliminary squad for the tournament on Saturday.
State news agency IRNA said that Azmoun was injured but media reports in March said he had been expelled from the national team after posting a picture on social media of a meeting with Dubai ruler Mohammed bin Rashid Al Maktoum.
Iran has attacked the United Arab Emirates, where Azmoun plays his club football, with drones and missiles during the war triggered by air attacks on the Islamic Republic by the United States and Israel.
Accusations of disloyalty in the Iranian media at that time clearly rankled with Azmoun and he addressed them in Wednesday's post.
"I want to speak from the bottom of my heart about some things that many people may not know, or about certain misunderstandings that may have led some to judge me too quickly," the 31-year-old wrote.
"I have always played for my national team with pride. When we won, I was proud of myself and my teammates. When we didn't, I was more upset than anyone else in the world, just like them.
"I love football, and I love the good and deserving people of my country, Iran. People whose kindness and unwavering support have always given me energy."
Azmoun, who is part of Iran's Turkmen ethnic minority, said as a teenager he had received a "very large financial offer" to represent another country.
"My answer was this: 'I am a son of Iran, and I want to play for my people and make them happy'," he wrote.
"I promised myself that every time I played for Iran, I would give everything I had to bring joy to the people who follow football with love -- especially the children in the most remote towns and villages who celebrate our victories.
"No matter where I play football, my identity, my heart, and my pride are Iran."
Azmoun concluded by wishing the World Cup squad success at the tournament.
"I wish success and pride for the players, coaching staff, and especially Amir Khan, at the World Cup," he wrote.
"Go out there and smash it, my friends, make the hearts of the people of Iran happy."
The Iran squad are currently at a training camp in Turkey, from where they will fly to their tournament base in the United States in the first week of June.