The State Railway of Thailand (SRT) plans to invest an additional THB300 billion for the second phase of the Bangkok–Nong Khai high speed railway (HSR) covering the section between Nakhon Ratchasima and Nong Khai. The budget increase proposal will be submitted to the Government of Thailand for final approvals in early 2023.

Additionally, an environmental impact assessment (EIA) for the second phase of the HSR project will also be submitted to the Office of Natural Resources and Environmental Policy and Planning (ONEP) for approval.

SRT will start inviting bids for works under the second phase by the end of 2023 once the budget increase has been finalised. A total of 13 contracts will be awarded for station construction and signalling systems.

The second phase covers a 356-km-long section of the Bangkok–Nong Khai HSR. Construction on this section is scheduled to commence in 2024 with completion targeted in 2028.