Thailand and Malaysia will discuss plans to build a wall along their shared border.
Thai officials confirmed the plan a day before Malaysian Prime Minister Najib Razak is set to meet his counterpart in Bangkok.
People-trafficking and the smuggling of drugs and weapons are among the crimes that have flourished along the 640 km Thai-Malay border, until a crackdown by Thailand last year disrupted regional trafficking routes.
Najib is to meet Thai Prime Minister Prayuth Chan-ocha on an official visit that will focus on security cooperation and investment.
The wall is on the agenda for the meeting, a Thai foreign ministry official said.
"It will be on the agenda during Najib's visit, but it will not be the biggest item on the agenda," foreign ministry spokesman Chinawut Setawat told Reuters at a regional meeting in the Laotian capital of Vientiane.
"It is still at the memorandum of understanding phase," said Colonel Yutthanam Petchmuang, a spokesman for Thailand's Internal Security Operations Command.
Najib's visit follows three deadly bomb attacks in southern Thailand over the past month, including a wave of bombs in tourist towns in August that Thai police have linked to Muslim separatists operating in the country's south.
