Prime Minister Prayut Chan-o-Cha will visit Laos for the foundation-laying ceremony of the fifth Friendship Bridge over the Mekong River on Friday.
Gen Prayut will be the guest of honour of Lao PM Phankham Viphavanh, government spokesman Anucha Burapachaisri said on Thursday.
Mr Anucha said the ceremony, when Gen Prayut is expected to lay a part of the foundation, was discussed in June when Mr Phankham visited Thailand.
Upon completion, the 1.1-billion-baht bridge and its approaches will stretch for 15 kilometres, crossing the Mekong River and linking Thailand's Bueng Kan province with Laos' Bolikhamxai.
The bridge was constructed under the Greater Mekong Subregion economic collaboration agreement between Thailand, Laos and Vietnam.
The bridge will provide an alternative to ferry services between Thailand and Laos and facilitate travel to China's Guangxi autonomous region.
Construction started in 2020, with about 57% now complete. Completion is scheduled for 2024. "The visit includes not only the ceremony but also a bilateral meeting between the countries on economic development," Mr Anucha said.