Mr Surapong, who is also the foreign minister, took over as chief of the Centre for the Administration of Peace and Order (Capo) on Monday from Deputy Prime Minister Pracha Promnok at the request of Prime Minister Yingluck Shinawatra.
During an announcement on the change, Pol Gen Pracha dismissed speculation that the move was a result of his inability to handle the rallies, saying that he is still a centre advisor and the situation is still under control.
The prime minister wanted Mr Surapong to help other countries better understand the political crisis, he went on.
The announcement of the Capo leadership change took place before the prime minister appeared on television to deliver a speech countering the demands of protest leader Suthep Thaugsuban.
Mr Surapong is seen to be closer to deposed prime minister Thaksin Shinawatra than Pol Gen Pracha.
Capo is charged with maintaining law and order and overseeing the enforcement of the Internal Security Act in Bangkok, Nonthaburi, one district in Pathum Thani and another in Samut Prakan.
On Monday Mr Surapong launched a campaign urging the international community to support democracy in Thailand.
He made the call during a briefing about the ongoing protests to 37 Bangkok-based ambassadors, eight international organisations and 23 diplomats at the National Defence College, which is being used as a temporary office for the Foreign Ministry while officials are unable to work at their usual premises, which is occupied by demonstrators.
Although the unrest is a domestic affair, Mr Surapong said he expected support from other countries.
He said the Pheu Thai-led government is facing the same fate as the previous administration of then premier Samak Sundaravej and Somchai Wongsawat who were dismissed from post.
"I hope you would make your stance for democracy clearly known and we hope that the United Nations bodies and agencies could make a similar show of support, especially in light of relevant conventions and international laws,'' he told the diplomats.
Mr Surapong said the government has refrained from the use of force and exercised utmost restraint and is determined to resolve the situation by peaceful means.
However, should the situation persist, the government will take appropriate measures to enforce the law according to international norms and standards, he added.
He said protesters are trying to justify unconstitutional acts under the guise of a so-called "people's revolt".
"Contrary to what happened in 2006, this time the military, particularly the heads of the armed forces, have not fallen into this political game. This is because they have learned from past experience that staging a coup is not acceptable to the international community,'' Mr Surapong said.