Donald Trump Jr has posed with an assault rifle featuring an image of Hillary Clinton behind bars and a religious symbol associated with medieval battles between Christians and Muslims.
The US President's eldest son proudly showed off the decorated gun in an Instagram post earlier this week.
"Nice day at the range," Mr Trump Jr wrote in the caption.
On the ammunition magazine is a depiction of former presidential candidate Hillary Clinton behind bars in a reference to one of his father's supporters' favourite chants "lock her up".
The gun is also decorated with an image of what's known as a Jerusalem cross - a large cross surrounded by four smaller ones - which was used during the Crusades, a series of religious wars between Muslims and Christians in medieval times.
A spokesperson for Donald Trump Jr told the Washington Post he was not making a political statement related to the looming conflict between US and Iran.
His post followed last week's US airstrike on Baghdad that killed Iranian general Qasem Soleimani. Iran has vowed to respond "in proportion" and pro-Iran factions are pressuring the Iraqi government to oust more than 5,000 US troops from their country.
Donald Trump Jr speaks at a political rally. Source: AAP
Mr Trump Jr's spokesperson said that it was common in gun culture to use emblems "depicting various historical warriors".
"Anyone claiming that the Jerusalem Cross is some sort of political statement, couldn’t be more ignorant," the spokesman said.
It's unclear if Mr Trump Jr owns the Crusader which costs more than $US2100 (AUD $3056).
Mr Trump Jr, who is a keen hunter, drew criticism last year for killing endangered sheep in Mongolia before obtaining a government permit.
Approval to hunt the argali, the largest living sheep, came through only after the August hunting expedition.
