"A Palestinian lawyer had watched the swearing-in ceremony and noticed that the clause "[to be loyal] to the people and its national heritage" was not included.
A longtime adviser to Abbas and a senior member of his Fatah party, Ishtaye and his 24-member cabinet took the oath of office at Abbas' headquarters in Ramallah, all vowing to respect the law and the Palestinian constitutional system, The Associated Press reported.
Palestinian President Mahmoud Abbas urged the new government "to fight the [Israeli] occupation with all legal means".
"I noticed the error and I posted a status update on Facebook", he told AFP.
Official Palestinian news agency WAFA said the oath was indeed repeated, adding that the mistake had been caused by a "typing error". Lawyer Nael al-Hawah said it could jeopardize the government's workings.
Addressing the ministers, Abbas said this mission is hard, adding that the new government will face many challenges, mainly the Deal of the Century, or the U.S. peace plan, whose content has all been declared.
Abbas's decision comes after forming a new government, which has ended the role of the national unity government, of which Hamas took part in its formation.
Palestinian Prime Minister Mohammad Ishtayeh talks during a swearing in of the new government in the West Bank city of Ramallah, Saturday, April 13, 2019.
The rival Hamas group that runs Gaza called the move blow to unity efforts that faltered since the two groups signed a new reconciliation deal in Cairo in October 2017, but disputes over power-sharing had blocked the implementation of the agreement.