He was speaking after Thai Prime Minister Yingluck Shinawatra met her Malaysian counterpart Najib Razak on the sideline of ongoing Asean Summit in Phnom Penh.
They agreed that the security measures at the Thai-Malaysian border checkpoint will be stricter out of suspicion that the culprits were those holding dual nationalities.
Both countries will also lend more cooperations including exchange of intelligence information in order to prevent reoccurrence of the violence.
The bomb explosions at Lee Gardens Plaza Hotel on Saturday killed three and injured hundreds of others. The attack took place a few hours after a deadly bomb attack in Yala's Muang district, killing 11.