The 253-kilometre section will connect the capital city of Bangkok andNakhon Ratchasima.
Arkhom said all Thai agencies concerned have conducted the study for six timesand there is still a problem over a section running past limestone mining areasin Saraburi.
The problem will be addressed only if the three mining companies agree to allowthe rail line to be built past the areas, he said.
He said Thailand’s Office of the Transport and Traffic Policy and Planning hasbeen asked to speed up talks with the three companies.
Chaiwat Thongkhamkhum, the office director, said he has negotiated with thethree companies, particularly over compensation for land expropriation.
An agreement is expected to be reached this month so that the construction ofthe 3.5-kilometre section between Klang Dong and Pang Asok stations can startin November.
Thenext stage is to extend the track to Nong Khai on the border with Laos to southernChina.
The project is part of China'shuge regional infrastructure plan to build a high-speed rail network connectingits southern city of Kunming with Laos, Thailand, Malaysia and Singapore.
In mid July, the Thai Government approved an investment worth 5.2 billion USDto build the Thailand-China high-speed railway.-VNA