"Today we say very clearly that taking such action is not justified ... It will not serve peace or stability, but will fuel extremism and resort to violence,” Gheit said in a statement published on the league’s website on Saturday.
"It only benefits one side; the Israeli government that is hostile to peace,” added the statement, Press TV reported.
US President Donald Trump is due to decide by Monday on whether to renew a six-month waiver on the relocation of the US diplomatic mission in Israel.
There are reports that the US president could again delay moving the embassy, but recognize Jerusalem al-Quds as the capital of Israel.
The Palestinian Islamic resistance movement Hamas has also warned the US against plans to relocate its embassy and to recognize the city as the capital of the Israeli regime.
The Palestine Liberation Organization (PLO) has also warned the US against the relocation of its diplomatic mission in Israel, saying all American embassies in the Arab world would have to close in the face of popular Arab outrage that would follow such an action.
PLO Secretary General Sa’eb Erekat said late last year that the potential move would deliver a death blow to any prospect of the resolution of the Arab-Israeli conflict, and would have his organization rescind all agreements with Tel Aviv.