The ministry has scrapped the plan to hold the event at Ratchadamnoen Avenue after protests by environmentalists and residents, he said.
It is also against the law to organise a motor racing event in inner Bangkok, according to Somsak.
"I can confirm that we cannot hold a Grand Prix on Ratchadamnoen Avenue," he said.
"The law, which took effect last month, prohibits a car racing event in inner Bangkok."
The ministry will try to organise the race in other provinces such as Phuket, he said.
"Phuket should be an ideal venue which meets our target to promote tourism," Somsak said.
"We still have time to prepare for the race."
Somsak said Khon Kaen or Nakhon Ratchasima may not be a suitable site because they lack accommodation and facilities to house hundreds of thousands of people during the Grand Prix.