Prime Minister Prayut Chan-o-cha will visit Laos for a foundation-laying ceremony for the fifth Friendship Bridge with the kingdom on Friday.
Gen Prayut will be Lao PM Phankham Viphavanh's guest of honour, government spokesman Anucha Burapachaisri said on Thursday.
Upon completion, the 1.1-billion-baht bridge will stretch for 15 kilometres, crossing the Mekong River, linking Thailand's Bueng Kan province with Laos' Bolikhamxai.
The bridge will be used as an alternative to ferry services between Thailand and Laos and ease travel between them and China's Guangxi autonomous region.
Construction started in 2020, with about 57% now complete.