"HISTORIC day for PEACE in the Middle East," tweeted Trump, trumpeting the imminent completion of "landmark deals that no one thought was possible."
"MORE countries to follow!" wrote the US leader, who hopes the peace deal will boost his reelection chances in November.
For the Mideast, the deals dubbed the Abraham Accords mark a distinct shift in a decades-old status quo where Arab countries have tried to maintain unity against Israel over its treatment of the stateless Palestinians.
The White House event will be the first time Arab nations have established relations with Israel since Egypt in 1979 and Jordan in 1994.
Hundreds of people were invited to attend and a symbolic handshake between the Arab representatives and Netanyahu has not been ruled out.