General David Petraeus, the chief of the US Central Command, which oversees US military operations in Iraq and Afghanistan, called the inscriptions, which he said he only learnt about on Wednesday, "disturbing".
|The inscriptions do not include actual text from the Bible but refer numerically to passages
"This is a serious concern to me and the other commanders in Iraq and Afghanistan because it indeed conveys a perception that is absolutely contrary to what we have sought to do," he said at the Centre for Strategic and International Studies in Washington on Thursday.
A Nato spokesman in Afghanistan acknowledged that the inscriptions were inappropriate but said the guns would remain in use for now.
Interviewed by Al Jazeera on Thursday, Colonel Gregory Breazile, of the Nato Training Command in Afghanistan, said: "We were told about it last night and when we looked into it, we noticed it was true.
"We started to take action and notify both the ministry of defence and our chain of command and they have all taken action so that we don't purchase any more of these sights.
"We gave the Afghan military these weapons. We are very disappointed, but it's a tiny little inscription and very hard to notice and I don't think it will be an issue in the field."
Breazile said: "We would have not bought these sights had we known they had these inscriptions on them."
Trijicon said it has inscribed references to the New Testament on the metal casings of its gun sights for over two decades.
But it offered on Thursday to stop putting Biblical references on all products manufactured for the US military.
The company also said it would provide, free of charge, 100 modification kits to the Pentagon to enable the removal of the references that are already on products that are currently deployed.
In a statement, Stephen Bindon, Trijicon's president and CEO, called the decision "both prudent and appropriate" and pledged to "move as quickly as possible to provide the modification kits for deployment overseas".
|Some members of the Afghan army have been seen using the controversial weapons [AFP]
Major Shawn Turner, a Pentagon spokesman, said the defence department "applauds" Trijicon's response.
"We will work to determine how best to quickly and prudently implement the remedies they have proposed," he added.
The inscriptions, which do not include actual text from the Bible, refer numerically to passages from the book.
The Advanced Combat Optical Gunsight rifle sights, used by New Zealand troops, carried references to Bible verses that appeared in raised lettering at the end of the sight stock number.
Markings included "JN8:12", a reference to John 8:12: "Then spake Jesus again unto them, saying, 'I am the light of the world: he that followeth me shall not walk in darkness, but shall have the light of life," according to the King James version of the Bible.
The Trijicon Reflex sight is stamped with 2COR4:6, a reference to part of the second letter of Paul to the Corinthians: "For God, who commanded the light to shine out of darkness, hath shined in our hearts, to give the light of the knowledge of the glory of God in the face of Jesus Christ," the King James version reads.
Tom Munson, Trijicon's sales director, said: "We don't publicise this. It's not something we make a big deal out of. But when asked, we say, 'Yes, it's there'."
The US Marine Corps was said by ABC News, which broke the news of the inscriptions, to have a $660m contract over multiple years with Trijicon to make 800,000 units of the product.
Trijicon has other contracts to supply the US army with the sights.
The sights are used on weapons used during the training of Afghan and Iraqi soldiers under contracts with the US army and Marine Corps.
Meanwhile, the US-based Muslim Public Affairs Council (MPAC) has called on Robert Gates, the US defence secretary, to withdraw the equipment immediately from combat.
"Having Biblical references on military equipment violates the basic ideals and values our country was founded upon," Haris Tarin, MPAC Washington director, said in a statement.
"Worse still, it provides propaganda ammo to extremists who claim there is a 'Crusader war against Islam' by the United States."
US military forces have repeatedly stated that their missions in Afghanistan and Iraq are secular and they have a ban on proselytising.