Cricket Australia said on Wednesday they backed Usman Khawaja's right to express his support for the people of Gaza but expected him to conform to International Cricket Council (ICC) rules banning displays on his playing equipment.

Batter 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.

According to Australian media reports, the Pakistan-born opener intended to wear the boots during the match, which starts at Perth Stadium on Thursday.

"We support the right of our players to express personal opinions, but the ICC has rules in place which prohibit the display of personal messages which we expect the players to uphold," Cricket Australia said in a statement.

Australia captain Pat Cummins, however, told reporters on Wednesday: "I spoke to him just quickly and he said he won't be.

"Just kind of drew attention to the ICC rules, which I don't know if Uzzie (Khawaja) was across beforehand.

"Uzzie doesn't want to make too big of a fuss."

Israel's ongoing assault on Gaza in response to the deadly Oct. 7 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.

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.

There was no immediate reply to a request for comment on the matter from the ICC.

Australia's Sports Minister Anika Wells, however, gave Khawaja her full backing.

"I have always advocated for athletes having the right to a voice and to speak up on matters important to them," she told local media.

"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.

"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."