Lt Gen Paradorn said this before attending the cabinet meeting at the Police Academy at Sam Phran on Tuesday.
He said the National Security Council had information that PDRC core members would be gathering at Lumpini Park, which is a well-secured area.
It was still not known where the UDD supporters would converge, he said, but there were three or four possible locations where they could rally, he added, but declined to give details.
It was not expected there would be any confrontation between the two rival groups, Lt Gen Paradorn said.
Anuwat Tinnarat, chairman of the northeastern UDD, said on Tuesday the UDD leadership had not announced where the red-shirts would rally this Saturday to demonstrate their readiness to protect the government.
He said the rally site might be somewhere in Bangkok or at Khao Yai Bonanza in Pak Chong district of Nakhon Ratchasima province.
No matter where the rally gathered, about 200,000 red-shirts from the 20 northeastern provinces would certainly be there. The total number of red-shirt supporters that day was expected to far exceed the 40,000-50,000 PDRC protesters, most of them from the South, who turned up for the PDRC rally in Bangkok on March 29, Mr Anuwat said.