Israeli Prime Minister Benjamin Netanyahu's new media adviser Ran Baratz has come under fire for making insulting remarks towards Barack Obama and John Kerry.

Baratz, in series of Facebook posts earlier this year, had insulted several public figures including Obama and Kerry, according to JTA. He had accused the U.S. President of "modern anti-Semitism" and referred to the Secretary of State as someone whose mental age doesn't exceed 12.

"Allow me to be a bit blunt, which is a break from my usual moderation. This is what modern anti-Semitism in a liberal Western country looks like. And, of course, it comes with a great deal of tolerance and understanding for Islamic anti-Semitism. The tolerance and understanding is so great that [Obama] is willing to give it a nuclear bomb," Baratz, a former university professor, wrote on his Facebook wall in March this year, The Jerusalem Post reported.

Netanyahu, who will be visiting the White House next week for a bilateral summit, slammed Baratz for making "unacceptable" remarks. He also decided to review Baratz's appointment as his new chief spokesperson.

"I have just read Dr. Ran Baratz's posts on the Internet, including those relating to the president of the state of Israel, the president of the United States and other public figures in Israel and the United States. Those posts are totally unacceptable and in no way reflect my positions or the policies of the government of Israel. Dr. Baratz has apologized and has asked to meet me to clarify the matter following my return to Israel," the Israeli Prime Minister said in a statement, according to NBC News.

State Department spokesman John Kirby said Mr Baratz's Facebook posts were "troubling and offensive."

"We obviously expect government officials from any country, especially our closest allies, to speak respectfully and truthfully about senior US government officials," State Department spokesman John Kirby said, according to BBC News.

"The secretary spoke with Prime Minister Netanyahu this morning and we understand that the prime minister will be reviewing this appointment when he returns from his visit to the United States."

The U.S. hinted Saturday that it would be unlikely that it will pursue a two-state solution between Israel and Palestine due to recent violence in Middle East.