The UAE's decision to normalise ties with Israel has been welcomed by some Arab countries, but despite cheer leading from the US, others have rejected the idea and many approach it with caution.
Secretary of State Mike Pompeo, who is on a Middle East tour that takes in Israel, Sudan, Bahrain and the UAE, expressed optimism Monday that more Arab nations will sign up.
Analysts say that Khartoum and Manama are most likely to follow in the footsteps of the UAE, which became only the third Arab nation to have diplomatic ties with the Jewish state.
Regional heavyweight Saudi Arabia, while not condemning the deal, has refused to normalise ties until Israel signs an internationally recognised peace accord with the Palestinians.
Contacts between Bahrain -- the first Gulf country to welcome the UAE-Israel deal -- and the Jewish state date back to the 1990s.
Bahrain, like most other Gulf countries, shares with Israel a common enemy in Iran, which Manama accuses of instigating protests by the nation's Shiite Muslim community against the ruling Sunni Al-Khalifa dynasty.
Manama is a close Saudi ally and is unlikely to establish official relations without Riyadh's blessing. But it could play an important intermediary role.
"While Saudi Arabia cannot directly normalise relations amid a stalemate in the peace process, Bahrain could become a hub for Saudi-Israeli exchange," said Andreas Krieg of King's College London.
A Bahraini government spokesperson echoed Saudi sentiment this week about the country's commitment to the Palestinian cause but added that Manama "makes its decisions based on its national and Arab principles, as well as its strategic security interests".
Sudanese officials have issued contradictory comments regarding a normalisation of ties, but a number of factors compel it to move in that direction.
Foreign ministry spokesman Haider Badawi said he was in favour of such an accord, but foreign minister Omar Gamaledinne said the issue "has never been discussed by the Sudanese government" and promptly fired the spokesman.
General Abdel Fattah al-Burhan, who heads Sudan's transitional sovereign council, met with Israeli Prime Minister Benjamin Netanyahu in Uganda in February.
Sudan, grappling with an acute economic crisis, seeks to be removed from a US blacklist as a state sponsor of terrorism, and normalisation of ties with close US ally Israel could help.
"They are extremely keen to have US sanctions lifted and they are under heavy UAE influence," said Cinzia Bianco, a research fellow at the European Council for International Relations.
Oman also quickly welcomed the UAE-Israel deal but said it was committed to "the legitimate rights of the Palestinian people who aspire to an independent state" with East Jerusalem as its capital.
The country is a close US ally but also has good relations with Iran. It maintains a policy of neutrality and has over the years played a mediating role in regional conflicts.
There have been several contacts between Oman and Israel, including in 2018, when the late sultan Qaboos received Netanyahu in Muscat.
Sultan Haitham, who was sworn in January after the death of Qaboos, is "already treading lightly due to possible economic-related grievances and would not risk such a controversial move at this time", said Bianco.
Qatar has not responded to the surprise announcement amid a protracted diplomatic standoff with the UAE, Saudi Arabia, Bahrain and Egypt -- who accuse it of supporting Islamist movements and conniving with Iran.
Doha, which is also close to the US, has an on-again, off-again relationship with Israel, after hosting an Israeli economic interests office from 1996 until 2000.
It is also heavily involved in the situation in the Gaza Strip, managing and funding welfare payments to the Palestinian people of the impoverished coastal territory with Israel's blessing.
"While Qatar cooperates with Israel in support of the Palestinian cause... it will not normalise relations as long as the peace process is stalled," Krieg said.
Kuwait, another close US ally, has also been silent on the Israel deal.
The rich emirate is the only country in the Gulf with a genuine political and parliamentary life, and permits sometimes lively public debate.
Some political groups and civil society organisations have condemned the UAE's decision to normalise ties with the Jewish state, while others have defended it.
But formalisation of ties with Israel is unlikely, as the National Assembly has capitalised "on hostility towards Israel to claim its place as the voice of the people", Bianco said.