(Updates with start of ceremony)
By Steve Holland and Matt Spetalnick
WASHINGTON, Sept 15 (Reuters) - U.S. President Donald Trump on Tuesday hosted leaders from the United Arab Emirates and Bahrain for the signing of agreements for normalizing relations with Israel's leader, making them the latest Arab states to break a longstanding taboo in a strategic regional realignment against Iran.
The White House ceremony capped a dramatic month when first the UAE and then Bahrain agreed to reverse decades of ill will toward Israel without a resolution of its decades-old dispute with the Palestinians.
Atop a balcony with Trump overlooking a crowd of several hundred on the White House lawn, Israeli Prime Minister Benjamin Netanyahu stood alongside Emirati Foreign Minister Sheikh Abdullah bin Zayed al-Nahyan and Bahrain's Foreign Minister Abdullatif Al Zayani.
The deals, denounced by the Palestinians, make them the third and fourth Arab states to take such steps to normalize ties since Israel signed peace treaties with Egypt in 1979 and Jordan in 1994.
Meeting Netanyahu earlier in the Oval Office, Trump said, "We'll have at least five or six countries coming along very quickly" to forge their own accords with Israel. But he did not name any of the nations involved in such talks.
Speaking from the balcony, Trump said: "We're here this afternoon to change the course of history," Trump said, calling it "a major stride in which people of all faiths and backgrounds live together in peace and prosperity."
He said the three Middle East countries "are going to work together, they are friends."
The back-to-back agreements mark an improbable diplomatic victory for Trump. He has spent his presidency forecasting deals on such intractable problems as North Korea's nuclear program only to find actual achievements elusive.
Bringing Israel, the UAE and Bahrain together reflects their shared concern about Iran's rising influence in the region and development of ballistic missiles. Iran has been critical of both deals.
(Reporting By Steve Holland and Matt Spetalnick, additional reporting by Dan Williams, Aziz El Yakoubi and Maha El Dahan; Editing by Howard Goller)