U.S. President Donald Trump, wading into the worst split between powerful Arab states in decades, said on Tuesday his trip to the Middle East was "already paying off" with leaders there taking a hard new line in accusing Qatar of funding of militant groups.

His blunt remarks cast the anti-Islamist speech he gave at a Riyadh summit in May as the inspiration for a decision by leading Arab powers to sever ties and transport links to Qatar in protest at what they say is its support for terrorism.

In fact, U.S. officials were blindsided by Saudi Arabia's decision to sever diplomatic ties with Qatar in a coordinated move with Egypt, Bahrain and the United Arab Emirates, current and former officials in Washington told Reuters.



"So good to see the Saudi Arabia visit with the King and 50 countries already paying off. They said they would take a hard line on funding extremism, and all reference was pointing to Qatar. Perhaps this will be the beginning of the end to the horror of terrorism!" Trump on Twitter.

The comments -- Trump's first about the rift between Qatar and major Arab nations over its alleged support of Iran and Islamist groups -- emerged at a delicate moment in the crisis as the leader of Kuwait was to meet in Saudi Arabia to try to mediate the dispute.

Qatar vehemently denies the accusations against it, calling them baseless. Ordinary Qataris, however, were to be found crowding into supermarkets to stock up on goods against the crisis.

Trump said, in apparent reference to top Gulf Arab powers Saudi Arabia and the UAE, that leaders he met on his trip had warned him Qatar was funding "radical ideology" after he had demanded they take action to stop financing militants.

It was not immediately clear what effect Trump's high profile intervention in the crisis would have.

U.S. officials had said on Monday that the United States would quietly try to calm the waters between Saudi Arabia and Qatar, arguing that the small Gulf state was too important to U.S. military and diplomatic interests to be isolated.

Qatar hosts 8,000 U.S. military personnel at al Udeid, the largest U.S. air base in the Middle East and a staging ground for U.S.-led strikes on the Islamic State militant group that has seized parts of Syria and Iraq.

There are also deep financial and business links between the two based on Qatar's leading world role in gas.