American Airlines Group Inc has said that it has signed a strategic partnership deal with Qatar Airways and is reviving its codeshare agreement.
The largest US airline also said that it is considering launching services from the United States to Doha.
Starting in 2015, the largest US carriers argued that their Gulf rivals were being unfairly subsidised by their governments, distorting competition and costing US jobs - something the Gulf carriers deny.
"The issues that led to the suspension of our partnership two years ago have been addressed, and we believe resuming our codeshare agreement will allow us to provide service to markets that our customers, team members and shareholders value," American chairman and chief executive Doug Parker said in a statement.
Qatar Airways Group chief executive Akbar Al Baker said in a statement that the strategic partnership "will bring together two of the world's largest airline networks, increasing choices for millions of passengers and providing seamless connectivity to a significant number of new destinations."
Pending government approvals, American will place its code on some Qatar Airways non-stop and connecting flights to and from the United States and Qatar Airways' hub in Doha, allowing American's customers access to additional destinations in the Middle East, east Africa and Asia that it does not serve.
Qatar Airways will place its code on select flights going beyond American's hubs in Dallas-Fort Worth, Chicago O'Hare, Philadelphia, Miami, New York-JFK and Los Angeles, and on American's international flights to and from Europe, the Caribbean, Central America and South America.
Parker and American president Robert Isom said in a note to employees that the airline has "gotten more strategic about where American's metal is deployed and when to enter joint businesses and alliances with partners to strengthen and complement our network. We will continue to act strategically to expand and deepen our global partnerships."
In June 2017, American notified Qatar of its decision to terminate its codeshare relationship.
Earlier this month, Brazilian budget airline Gol signed a codeshare agreement with American Airlines. American also announced it was expanding its relationship with Alaska Airlines, which is also joining the global airline network oneworld that includes Qatar and American.
In April 2019, US secretary of state Mike Pompeo said that the administration was scrutinising Qatar Airways' acquisition of a 49% stake in Air Italy, which had been flying to US destinations since 2018 in a move seen by US lawmakers as flouting a deal not to add new flights to the domestic market.
Qatar Airways and another investor agreed earlier this month to put Air Italy into liquidation.