He would travel to Singapore on Tuesday and stay until Thursday to attend a retreat for his counterparts in Asean.
However the ministry had earlier indicated that the minister's first foreign visit would be to neighbouring Laos.
That trip was postponed because Noppadon was needed in Bangkok to help develop the government's policy speech to be presented Monday to parliament, the official said.
He also responded to a news report that ousted Thaksin is in Singapore, saying Thaksin would not be there when he visits Singapore.
"I will go Singapore to attend the Asean foreign ministers' meeting, not to meet with Thaksin. By the time I arrive, he probably will not be there any longer," he told reporters.
"I do speak with him from time to time. He will definitely return to Thailand, but not today... He will be back before May," Noppadon said.
Thaksin's wife told a court last month that he would return to Thailand in May to defend himself against the charges, though the date of his return remains the subject of widespread speculation.