Navy chief Adm Adung Phan-iam is repeating his call for Defence Minister Sutin Klungsang to approve the navy's submarine procurement plan, after Mr Sutin retained his position following the latest cabinet reshuffle.
"The defence minister has promised to finalise the talks [with China] on submarine procurement as soon as possible," Adm Adung said.
A source said Mr Sutin is due in China next month.
Adm Adung also said the navy has submitted its budget proposal for the 2025 fiscal year, before reiterating his call for Mr Sutin to "attach importance to protecting the nation's maritime territory and interests".
''We want the government to attach importance to preparing maritime fleets to protect the nation's maritime interests and territory," he said.
When asked if the navy is still planning to accept a frigate in lieu of the two submarines, Adm Adung said the matter wasn't included in the budget proposal for the 2025 fiscal year, though he said it may be included in the 2026 budget request.
He noted that the navy "has a very limited fleet of warships", and that more ships are needed so the navy can carry out its duties properly.
After assuming the Defence Minister position in September last year, Mr Sutin announced that he would shelve the navy's submarine procurement programme and push for a frigate instead.
The decision came following a protracted impasse on the choice of engine that would be fitted on the submarines Thailand had ordered. The navy wanted to fit a German engine on the submarines, but Berlin won't allow a German engine to be fitted on a Chinese submarine.
China Shipbuilding & Offshore International Co (CSOC) offered to fit Chinese engines on the submarines, but the navy decided against it as the engines have yet to undergo performance testing.
Mr Sutin is now looking to finalise talks with China on the plan to procure alternatives to the submarines.
He had earlier said that China was open to the proposal to procure either two offshore patrol vessels (OPVs) or a frigate instead of a S26T Yuan-class submarine.
However, the swap proposal has raised concerns at CSOC, which has reportedly finished about half of the first submarine ordered by the navy.