The flood of Syrian refugees has been straining Lebanon for several years, and the Lebanese have now responded by imposing visa restrictions on Syria for the first time ever.
Residents from the neighboring Arab states have traditionally been able to travel back and forth easily despite relations that have often been tumultuous. But more than 1 million Syrian refugees have entered Lebanon since Syria's civil war began in 2011, placing a huge burden on Lebanon, a country of just 4 million people.
Syrians will be allowed to enter Lebanon on humanitarian grounds, but they will now need visas, Lebanese officials said.
"The goal is to prevent [Syrians] from taking refuge" in Lebanon and "to more seriously regulate the entry of Syrians," Social Affairs Minister Rashid Derbas told Agence France-Presse.
The minister has estimated that the Syrian war and the refugee crisis have cost Lebanon some $20 billion.
Large numbers of Syrian refugees have also entered Jordan and Turkey, which have created refugee camps to accommodate them. In contrast, most Syrians entering Lebanon have moved in among the general population.
The influx has created tensions, and the Lebanese have responded in a number of ways, including curfews imposed on refugees in a number of towns and villages. The Syrians, meanwhile, have complained of abuses by some of the Lebanese curfew patrols.
More than 3 million Syrians have fled their homeland since the war began, and some 6.5 million more have been displaced inside Syria.