On Monday, Dana Shell Smith, US ambassador to Qatar, posted an embassy statement saying the "US supports Qatar's efforts in combating terrorism financing, and appreciates its role in coalition against ISIL".
His defence secretary, James Mattis, also spoke to his Qatari counterpart to express commitment to the Gulf region's security.
The United Arab Emirates, along with several other powerful Arab states, severed diplomatic ties with fellow Gulf state Qatar on Monday over its alleged support for Islamist groups and Iran.
Trump publicly accused key regional ally Qatar of funding extremism, while tacitly backing a blockade of the emirate, home to the Al-Udeid Air Base near Doha where around 10,000 USA military personnel are stationed.
White House Press Secretary Sean Spicer contradicted the president's sentiment on Tuesday by saying Trump was "very heartened" by his "constructive conversation" with the emir of Qatar two weeks ago. Trump said on Twitter, claiming his visit to Saudi Arabia was "already paying off".
Qatar has for years parlayed its enormous gas wealth and media strength into broad influence in the region. But Gulf Arab neighbours and Egypt have always been irked by its maverick stances and support for the Muslim Brotherhood, which they regard as a political enemy.
Bahrain, Egypt and the United Arab Emirates were among those who joined Saudi Arabia on Monday in cutting diplomatic ties with Qatar.
Adel Al-Jubeir said: "Nobody wants to hurt Qatar". "Restrictions on vessels calling into Qatar and associated uncertainty could impact the inherent value of crude loading from Qatar", it said.
Qatar is home to the largest American airbase in the Middle East - making Trump's statement all the more surprising. But analyst Saeed Wahabi said Qatar has been unwilling to enforce restrictions on terror financing and partner with the USA on counter terrorism the way Saudi Arabia has.
The rift has affected oil prices, hit travel and shipping, and left supermarkets in Qatar short of goods.
In this May 14, 2010 photo, a Qatari woman walks in front of the city skyline in Doha, Qatar.
Speaking to the BBC, Qatar's foreign minister Sheikh Mohammed bin Abdulrahman Al-Thani gave the first response to Trump's tweets, denying any Qatari funding "of terrorism".
USA officials told CNN they believe Russian Federation was trying to "cause rifts among the US and its allies".
"If Tillerson knew he was not passing that information down to folks", the official said.
Meanwhile, U.S. President Donald Trump on Tuesday appeared to take credit for the countries' decision to sever ties with Doha. India's exports to Doha are tiny at $1.05 billion in 2014-15.
Traders on global markets anxious that Riyadh's allies would refuse to accept LNG shipments from the Gulf state, the world's largest liquefied natural gas exporter, and that Egypt might even bar tankers carrying Qatari cargoes from using the Suez Canal as they head to Europe and beyond.
From landing at Saudi Arabian airports, the general authority of civil aviation issued a decree prohibiting all Qatari Airlines and Qatar Airways.
The real reason for the rupture between Saudi Arabia and Qatar was the conflicting national policies toward Iran, Lazare explained.
"However, we don't see any cut or default signs at this stage and we estimate that the situation will be resolved shortly through diplomatic channels", said the source at the Energy Ministry.