Israel will not co-operate with any "external investigation" into the death of journalist Shireen Abu Aqla, BBC reports.
Defence Minister Benny Gantz said it was "a mistake" for US authorities to open an investigation into the killing.
The Palestinian-American correspondent was shot in the head while covering a raid in the occupied West Bank in May.
Eyewitness said she was shot by Israeli troops, while an Israeli official said there was a "high probability" she was killed by one of its soldiers.
On Monday, US media outlet Axios reported that the US Justice Department had informed Israel`s Justice Ministry that the Federal Bureau of Investigation (FBI) had opened an investigation into her death.
Gantz said that the Israel Defence Forces (IDF) has conducted a "professional, independent investigation" that had been shared with US authorities, adding that he had told American officials that "we stand by the IDF`s soldiers, that we will not cooperate with an external investigation, and will not enable intervention to internal investigations".
Abu Aqla - one of the most recognisable faces of journalism in the Arab world - was killed on 11 May while covering an Israeli army raid in Jenin refugee camp in the West Bank, which had witnessed gun battles between Israeli soldiers and Palestinian militants. She was wearing a helmet and blue flak jacket marked with the word "press" at the time of her killing.
Eyewitnesses and Palestinian officials said she was shot by Israeli troops - a finding later backed by the United Nations and multiple investigations by media outlets. A US review also found it was "likely" that Israeli soldiers fired the fatal bullet.
In September, a senior IDF official said there was a high probability that she was shot "by mistake by an IDF soldier, and of course he didn`t identify her as a journalist".
The official added that investigators had spoken to the soldier involved: "He told us what he did; and if he did it, it was done by mistake.
"I want to emphasise the fighting environment that these soldiers were under. They were confined in a protected vehicle with multi-dimensional fire from every direction."
However, video evidence from the moment Abu Aqla was shot does not support the claim of militant gunfire in the spot that journalists and bystanders had gathered.
Israeli troops were believed to be 200m (656ft) away, and the footage shows repeated fire for several minutes towards the area where the journalists were walking.
Abu Aqla was born in Jerusalem but spent time in the United States, obtaining US citizenship. She spent most of her career covering the Israel-Palestinian conflict, notably for Al Jazeera`s Arabic news channel.
"I chose journalism to be close to people. It might not be easy to change the reality but at least I could bring their voice to the world," she once said.
