Mr. Trump made the remarks while hosting the emir of Qatar at the White House on Tuesday for meetings as he continues his US tour.
Qatar has since taken steps to address US concerns, even allowing Treasury Department officials into its central bank to improve accountability for controls to prevent terror funding. Trump had followed the lead of Saudi Arabia and the United Arab Emirates in taking a hard line against Qatar, saying the country needed to scale back ties with Iran and stop funding extremism. He repeated the point several times as reporters and cameras were allowed in briefly for the start of their meeting.
Final summer season, Trump took the aspect of Saudi Arabia and different Persian Gulf nations of their ongoing diplomatic disaster with Qatar.
"I want to make something very clear, Mr. President", the Qatari emir said. Qatar denies all these prices.
The two leaders agreed in a telephone call that members of the six-nation Gulf Cooperation Council "can and should do more to increase coordination with each other and with the United States", the White House said in a statement.
The emir is also thanking Trump for his role in trying to solve the crisis involving Qatar and America's allies in the Persian Gulf. Qatar denies that cost however has taken steps to deal with US considerations.
Over the months, Trump's administration has lost patience with the crisis, especially after an early US effort to mediate a resolution sputtered.
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Special Counsel Robert Mueller had earlier indicted these employees for seeking to conduct "information warfare" against the U.S. Republican chairman of the Senate Judiciary Committee, Chuck Grassley, announced on April 4 that the testimony would take place.
Earlier this week, USA officials said the Trump administration was postponing until September a summit with Gulf Arab leaders that had been planned for May.
Qatar's neighbors had also been infuriated by its willingness to host dissidents from across the Gulf and to allow broadcasts critical of them by Doha-based Al Jazeera. "There are a lot of good things happening". As a key example of Qatar's efforts on counter-terrorism, the State Department pointed out that in March, Qatar added roughly two dozen people and entities on its terror blacklist.
Despite the past tensions, there were signs that Trump was warming to the Qataris.
The US has approved a $300m sale of guided missiles to Qatar.
Mattis welcomed the emir of Qatar to the Pentagon today for a meeting to reaffirm the strategic security partnership between the USA and Qatar.
The leaders are set to hold a meeting and working lunch that the White House said would focus on strengthening ties, including security and economic issues.
Sheikh Tamim said his nation hosts more than 10,000 USA servicemen and women and work with Washington in countering terrorism.