The Gulf nations of Bahrain and Qatar agreed to restore diplomatic relations late Wednesday.
Bahrain had been the last holdout of four Arab nations that imposed a boycott on Qatar in 2017.
They were angered by Qatar’s support for Islamist groups that rose to power in some countries following the 2011 Arab Spring protests, which the other autocratic nations viewed as terrorist organisations.
The boycott was lifted at the start of 2021, and Saudi Arabia, the United Arab Emirates and Egypt have restored ties with Qatar since then, with top leaders paying official visits in recent months.
Bahrain and Qatar each issued official statements announcing the decision to restore relations following a meeting between their delegations at the headquarters of the Gulf Cooperation Council, a six-nation bloc of which both are members, in the Saudi capital of Riyadh.
The four nations had severed all ties to Qatar, and at the height of the crisis there was even talk in local media of digging a trench along the 87-kilometre (54-mile) border between Qatar and Saudi Arabia and filling it with nuclear waste.