The United Arab Emirates (UAE) and Bahrain have signed agreements to normalise relations with Israel in what Donald Trump has hailed the "dawn of a new Middle East".
The deal will make them the third and fourth Arab states to take such steps to normalise ties since Israel signed peace treaties with Egypt in 1979 and Jordan in 1994.
"The people of the Middle East will no longer allow hatred of Israel to be fomented as an excuse for radicalism or extremism," Trump said at the White House ceremony.
Mr Trump said he hopes other countries will follow suit, but the Palestinians have urged them not to while their conflict remains unresolved.
For decades, most Arab states have boycotted Israel, insisting they would only establish ties after Israel's dispute with the Palestine was settled.
Israeli Prime Minister Benjamin Netanyahu welcomed the deals, saying, "This day is a pivot of history; it heralds a new dawn of peace."
Ammar Hijazi, assistant minister of multilateral affairs for the Palestinian Authority, said the signing of the accords was "a sad day".
Hijazi called the White House signing ceremony a "photo op" that "only crowns Israel as the policeman of the region" and paves the way for more US weapons sales to the region.
Speaking to Al Jazeera, Hijazi said that 'the only path for peace for the Palestinians is ending the brutal Israeli occupation and granting the Palestinians their inalienable rights for self-determination'.
Prior the UAE and Bahrain, the only other Arab countries in the Middle East to recognise Israel officially were Egypt and Jordan, who signed peace treaties in 1978 and 1994 respectively.
Mauritania, a member of the Arab League in north-west Africa, established diplomatic relations with Israel in 1999 but severed ties in 2010.
Although a diplomatic win for Netanyahu, the historic ceremony has taken place while he faces criticism at home for his handling of the coronavirus pandemic and a corruption trial on charges of bribery, fraud and breach of trust that have led to frequent street protests. The prime minister has dismissed this as a left-wing political witch-hunt aimed at unseating him.
Before the UAE agreement in August - which included the suspension of Israel's controversial plans to annex parts of the occupied West Bank - Israel had had no diplomatic relations with Gulf Arab countries.
Palestinians view the new agreements as weakening a long-standing pan-Arab position that calls for Israeli withdrawal from occupied territories and acceptance of Palestinian statehood in return for normal relations with Arab countries.
The agreements represent the most significant diplomatic achievement of the Trump administration. While the details of the agreements are not yet public, there will be embassies, commercial deals and the opening of travel links between the countries.
Israel also signed separate agreements with each of the Gulf states and the US joined all three in signing a common document known as the Abraham Accords, which the White House described as a "declaration of peace".