Khawaja had the messages "Freedom is a human right" and "All lives are equal" written on his boots in the colours of the Palestinian flag in Tuesday's training for the first test against Pakistan.
Australia captain Pat Cummins said on Wednesday that the Pakistan-born opener had agreed not to display the messages during the match when it started on Thursday, but Khawaja later posted an emotional video on the social media site X.
"The ICC have told me I can't wear my shoes on the field because they believe it's a political statement under their guidelines," he said.
"I don't believe in this though. It's a humanitarian appeal. I will respect their view and decision, but I will fight it and seek to get approval. Freedom is a human right."
Israel's ongoing assault on Gaza in response to the deadly October 7th cross-border attacks by Hamas has killed at least 18,205 Palestinians, according to the Gaza health ministry.
The ICC Code of Conduct forbids players wearing, displaying or conveying messages through arm bands or other items on clothing or equipment without prior approval.
Messages related to political, religious or racial activities or causes are not allowed.
When asked for comment on Wednesday, the ICC directed reporters to the relevant regulations which make clear that the global governing body is the final arbiter of what is allowed and what constitutes a "political, religious or racial cause."
England batsman Moeen Ali, who like Khawaja is a Muslim with Pakistani heritage, was banned by the ICC in 2014 from wearing wristbands featuring the slogans "Save Gaza" and "Free Palestine".
The ICC did, however, allow players to "take the knee" before international matches in support of the 'Black Lives Matter' movement in 2020 and 2021.
"What I've written on my shoes isn't political. I'm not taking sides. Human life to me is equal," Khawaja added.
"One Jewish life is equal to one Muslim life is equal to one Hindu life, and so on. I'm just speaking up for those who don't have a voice."
Cricket Australia said in a statement that Khawaja had a right to express his opinion but they expected him to conform to the ICC rules banning displays on his playing equipment.
Australia's Sports Minister Anika Wells gave Khawaja her full backing.
"Usman Khawaja is a great athlete and a great Australian. He should have every right to speak up on matters that are important to him," she said.
"He has done so in a peaceful and respectful way. He has done so as an individual and expressed an individual opinion that does not compromise the Australian cricket team's obligations to the ICC."
