Two US Navy vessels arrived in Doha to take part in a joint military exercise with the Qatari Emiri Navy on Wednesday, Qatar news agency (QNA) reported.
The crews of the two vessels were received by Qatari navy officers, QNA said, citing a statement from the country's defense ministry.
Turkey sent its foreign minister to Qatar as part of a drive to resolve the crisis. Kuwait, a neighbor and a member of the Gulf Cooperation Council (GCC), also has been mediating.
Meanwhile, US Secretary of Defense Jim Mattis and his Qatari counterpart Khalid al-Attiyah signed a letter of agreement for a $12-billion sale of 36 U.S.-manufactured F-15 fighter jets.
The drills and the jet deal come amid a political and economic blockade of Qatar by its neighbors.