RAMALLAH, March 29 (Xinhua) -- The Office of Palestinian President Mahmoud Abbas slammed on Thursday the remarks of U.S. Ambassador to Israel David Friedman as "a shocking intervention" in the Palestinian internal affairs.

"David Friedman's remarks against Abbas and the Palestinian leadership are a shocking, unacceptable and a clear intervention in the Palestinian internal affairs," said Nabil Abu Rudeineh, Abbas' aide in an official statement.

The Palestinian state-run WAFA news agency quoted Abu Rudeineh as saying that "the Palestinian people will not accept any intervention of any foreign side whoever it is to decide their determination."

Friedman has reportedly sent a threatening message to Abbas that if he (Abbas) does not go for peace negotiations with Israel, Washington will look for a possible Palestinian alternative to fill this vacuum.

Abu Rudeineh said "it seems that Friedman is speaking on behalf of Israel rather than speaking on behalf of the United States and puts himself in a position that defends Israel and the settlers."

"He (Friedman) does not represent the interests of the United States, he represents a mentality that only wants to increase tension and damage the image of the U.S. people," said Abu Rudeineh.

The Abbas' aide went on saying that "this mentality serves the interests of the extremist settlers which created the mentality of the Islamic State (IS), extremism and violence," adding that the U.S. administration "must put an end to such unashamed behaviors."

He called on the U.S. administration "to make a clear position towards these endless (Friedman) remarks which contradict with the diplomatic regulations."

Two weeks ago, Abbas described Friedman as "the son of the dog" because of his favorable position on Israeli settlement. The Palestinians had earlier repeatedly slammed Friedman for his endless remarks that support Israeli settlements.

Tension between the United States and the Palestinians mounted after Trump declared last December that Jerusalem is the capital of Israel and that he intends to move his country's embassy from Tel Aviv to the city.

Following Trump's declaration, the Palestinians announced that the United States is no longer a sponsor for the Middle East peace process and called for an international peace conference with a mechanism that ends the occupation and establish an independent Palestinian state on 1967 territories with East Jerusalem as its capital.

Talks, sponsored by the United States, between Israel and the Palestinians had halted since April 2014 after it went on for nine months without making any significant breakthrough due to differences on settlement, borders and security issues.

Meanwhile, Abbas' Fatah Party had also condemned in an official emailed press statement on Thursday Friedman's remarks and his threats to find a Palestinian alternative that would agree to hold peace talks with Israel.

"President Mahmoud Abbas is the elected president of all the Palestinians and he is the one who leads the Palestinians towards independence and the one who does all his best to protect Jerusalem and all its holy sites," said the statement.

Fatah Party called on the United States "to immediately stop this illusion," adding "the U.S. can never find one single Palestinian who is willing to make concessions over the stable legitimate rights of the Palestinians."

It added that the U.S. stances "are increasing the isolation of the United States due to its hostile policies against the Palestinian people which contradict with the international resolutions and the positions of most of the world's countries."