The White House National Security Council said the delay was not tied to the tensions over Qatar.
The Trump administration is postponing until September a summit with Gulf Arab leaders that had been planned for this spring, according to five US officials.
The decision to delay the May summit with the six-nation Gulf Cooperation Council reflects a crowded diplomatic calendar, and the fact that President Donald Trump is without a secretary of state until the Senate confirms current CIA director Mike Pompeo, two of the officials said.
Other sources, however, told Reuters the delay is also a nod to the fact that Washington has made little progress so far in ending the Qatar crisis.
"This was entirely our decision," one US official, speaking on condition of anonymity, said of the delay.
"We have too many irons in the fire in May," the official added, noting that Trump may be meeting North Korean leader Kim Jong Un next month, and that Pompeo has yet to be confirmed to replace Rex Tillerson.
A spokeswoman for the White House National Security Council said the delay was not tied to the tensions over Qatar, adding that, "President Trump is committed to resolving the Gulf dispute this month."
Trump met with Saudi Crown Prince Mohammed bin Salman at the White House on March 21. He is due to meet with the Qatari Amir next week, followed by a meeting with His Highness Sheikh Mohamed bin Zayed Al Nahyan, Crown Prince of Abu Dhabi and Deputy Supreme Commander of the UAE Armed Forces.
Trump spoke by phone with Saudi King Salman Bin Abdulaziz Al Saud, Custodian of the Two Holy Mosques on Monday, emphasizing the importance of resolving the Gulf dispute, the White House said.
Saudi Arabia, the UAE, Bahrain and Egypt cut off travel and trade ties with Qatar last June for backing Iran, and supporting terrorism.
A senior US official said the summit was discussed during Salman's Washington visit, and there was agreement that it would be better to delay the meeting until after the holy month of Ramadan, which ends in mid-June.