The countries Saudi Arabia, the United Arab Emirates, Egypt and Bahrain released separate and apparently coordinated statements saying they would cut air, sea and land links with Qatar, which hosts a forward base for the U.S. militarys Central Command and is home to the widely watched Al Jazeera network.
Some other countries later joined the four-nation bloc in cutting ties with Qatar, which is also the venue for the 2022 World Cup.
The feud the most serious in decades among some the regions most key Western allies has been simmering for years as Qatar increasingly flexed its political muscle across the region, including backing the Muslim Brotherhood.
Qatars outreach often raised conflict with Saudi Arabia and the United Arab Emirates, both of whom have sought to exert their own influence across the Arab world.
The diplomatic break came just weeks after President Trump met with Arab and Muslim leaders in Saudi Arabia and called for a unified front against extremism and regional influence by rival Iran.The visit was hailed by the Trump administration as a success, but analysts in the Middle East said at the time that it would likely aggravate local disputes and ultimately hamper U.S. efforts at coalition building.
Trumps trip, they said, amounted to a U.S. endorsement of the Saudi-led bloc that has increasingly demanded that other Arab states including Qatar fall in line with Riyadhs positions, including a hard line against Iran, support for Saudi-allied rulers and opposition to transnational Islamist groups.
But Saudi Arabia is often accused of indirectly fueling militant views through its strict Wahhabi brand of Islam.
The Brotherhood and affiliated groups, which favor Islamist-inspired policies, are seen by many Arab leaders as threat and have faced sharp crackdowns around the region since being ousted from power in Egypt in 2013.
As Trump left the region, the result appeared to be an unusually bitter feud between Persian Gulf monarchies that have long boasted in public of their brotherly relations, while competing behind the scenes for influence in a region riven by uprisings and wars, and haunted by resurgent militant groups
The internationally recognized government of Yemen also broke ties with Qatar, Saudi news media reported. The stance appeared largely symbolic, however. The Yemeni government of President Abed Rabbo Mansour Hadi, which is backed by Saudi Arabia, operates largely in exile because of the countrys civil war and enjoys dwindling support in Yemen itself.
The Indian Ocean nation of the Maldives also joined the break with Qatar. But two other Persian Gulf states, Kuwait and Oman, which have frequently played mediating roles in Arab disputes, did not announce any measures against Qatar.
Secretary of State Rex Tillerson and Defense Secretary Jim Mattis, traveling in Australia on Monday, asserted that the developments would not affect the U.S.-led coalition fighting Sunni extremist groups in the Middle East.
What were witnessing is a growing list of irritants in the region that have been there for some time, and obviously they have now bubbled up to a level that countries decided they needed to take action in an effort to have those differences addressed, Tillerson said.
Other nations with strategic ties in the region quickly urged for efforts to keep the diplomatic spat from widening.
We see the stability in the Persian Gulf region as our own unity and solidarity, Turkeys Foreign Minister Mevlut Cavusoglu told reporters in Ankara.
In Russia, a Kremlin statement said a stable and peaceful Persian Gulf region was crucial to the region.
The United States uses bases in several of the countries to launch air operations against the Islamic State extremist group. The U.S. headquarters for the air war is located at the Al Udeid Air Base in Qatar.
Tillerson and Mattis asserted on Monday that thePersian Gulf feud would not affect the U.S. coalition fighting against the Islamic State.
For years, Qatar has drawn the ire of Arab neighbors for its support of the Muslim Brotherhood and affiliated Sunni Islamist groups, as well as for its sponsorship of the Al Jazeera television channel, which hosts frank discussions of politics in the region while also amplifying Qatars pro-Islamist views.
Qatar is also among severalPersian Gulf countries, including Kuwait, Bahrain and Saudi Arabia, accused in recent years of looking the other way as its citizens privately sent money to Islamist militants abroad, including in Syria.
In response to Qatars diplomatic isolation on Monday, the U.S. ambassador to Qatar, Dana Shell Smith, posted news releases on Twitter that were supportive of Qatars efforts to combat terrorism financing. The U.S., one read, supports Qatars efforts to deny terrorist financiers access to its financial system.
The statements by the Arab countries Monday, however, went beyond far beyond the usual criticism of Qatar for supporting Sunni extremists, accusing it of interference in conflicts from Yemen to the Sinai Peninsula.
The battery of charges included some that appeared implausible. Saudi Arabia, for instance, accused Qatar of supporting Yemens Houthi rebels even though Qatar has participated in a Saudi-led coalition fighting against the Houthis.
Bahrain, a stalwart ally of Saudi Arabia, accused Qatar of financing groups associated with Iran to subvert and spread chaos in Bahrain.
Qatars Foreign Ministry called the measures unjustified in a statement and said the decision to sever ties was a violation of the countrys sovereignty, and based on claims and allegations that have no basis in fact.
The first signs of the intensifying feud emerged soon after Trumps visit to Saudi Arabia. In the days that followed, the Saudi government and its allies attacked Qatar for statements allegedly made by Qatars emir that were sympathetic to Iran and militant groups like Hezbollah and Hamas.
Qatar later said the statements, which were posted on the state news agency, were fake and that the agencys website had been hacked. That explanation, however, did not stop the attacks on Qatar from media outlets loyal to the Saudi or Emirati governments.
It remained unclear what exactly had led the Arab states to move so suddenly and forcefully to isolate Qatar.
The crux is, you have a country following a different policy than the Saudis and their partners, said Mishaal Al Gergawi, the managing director of the Delma Institute, a political consultancy in the United Arab Emirates.
In addition, he said, Saudi and otherPersian Gulf leaders felt after the Riyadh conference that the Trump Administration was far more sympathetic to their concerns than President Obama had been.
Now that you have a post-Arab Spring reconstitution of some kind alliance, he said, there is really little room for dissent on this side of thePersian Gulf.
Iran a main regional rival of Saudi Arabia and its Persian Gulf allies linked Trumps visit to the harder line against Qatar.
What is happening is the preliminary result of the sword dance, wrote Hamid Aboutalebi, a top aide to Iranian President Hassan Rouhani, in a tweet making reference to Trumps trip last month to Saudi Arabia and his participation in a traditional dance.
Later, Irans foreign minister, Mohammad Javad Zarif, posted a Twitter message noting that the diplomatic spat broke out during the Muslim holy month of Ramadan.
Neighbors are permanent; geography cant be changed, Zarif wrote. Coercion is never the solution. Dialog is imperative, especially during blessed Ramadan.
Oil prices initially rose on news of the diplomatic break, then later dropped back as political uncertainty weighed on energy markets. Qatar is a major supplier of liquefied natural gas and other gas-related products.
Qatar, a peninsula nation that shares its only land border with Saudi Arabia, was left facing potentially catastrophic isolation on Monday, as airlines in the UAE and Saudi Arabia announced they were halting flights, and as a local Qatari news outlet reported that residents there were flocking to supermarkets to stock up on food.
Dan Lamothe in Sydney, Heba Farouk Mahfouz in Cairo and Brian Murphy and Anne Gearan in Washington contributed to this report.
