Cambodian King Norodom Sihamoni appointed Hun Manet as the new prime minister on Monday after incumbent Prime Minister Samdech Techo Hun Sen announced he was stepping down.

The monarch signed a royal decree to designate Hun Manet, 45, as the new prime minister for a five-year term following a request from Hun Sen.

"The designated prime minister of the Kingdom of Cambodia has duties to prepare the members of the government in order to ask for the adoption of confidence from the National Assembly," Sihamoni said in the royal decree.

"This royal decree takes effect from the day of signature," he added.

Hun Manet, along with his new cabinet members, will need to win a vote of confidence in the National Assembly slated for Aug. 22 in order to officially become the new prime minister, and he is expected to be sworn in on the same day.

In a thank-you letter to the king, Hun Manet said it was the greatest honor in his life to receive a great opportunity to serve "his most-loved motherland and people in this noble position".

"I, along with all dignitaries in the royal government of the seventh legislature of the National Assembly, are committed to fulfilling this noble national mission with heroism, honesty and high responsibility to serve the motherland and the people of Cambodia," he said.

Hun Manet vowed to continue ensuring the protection of national independence, sovereignty and territorial integrity, as well as the throne and the constitutional monarchy.

He also pledged to continue ensuring national peace and stability, promoting further development, improving the living standards of the Cambodian people, and enhancing the national prestige on the international arena.

The appointment came after the ruling Cambodian People's Party (CPP) led by Hun Sen won a landslide victory in the July 23 general election, gaining 120 out of 125 seats in the National Assembly.

Hun Manet is currently a member of the CPP's Standing Committee and a deputy commander-in-chief of the Royal Cambodian Armed Forces.

Hun Sen announced on July 26 that he would step down as the prime minister after having held the post since Jan. 14, 1985, handing the reins of power to his eldest son Hun Manet.

However, the 71-year-old leader said he will remain the CPP's president and will take the position of President of the Senate in a Senate Election on Feb. 25 next year.

Hun Manet, father of three children, graduated from the U.S. Military Academy at West Point in 1999, received a Master's Degree of Arts in Economics from New York University in 2002, and earned a Doctorate Degree in Economics from the University of Bristol, Britain, in 2008.

Kin Phea, director-general of the International Relations Institute of Cambodia, a think-tank under the Royal Academy of Cambodia, said on Monday that Hun Manet is the deservedly qualified candidate for the position of the new prime minister.

"In addition to his high education from overseas, he has been equipped with the best experience both in military and political affairs, with his father as the best-guiding light," he told Xinhua.

"He has been actively involved in politics and is popular among Cambodian people, especially among the youth," Phea said. "He has a unique leadership style that can be described as a great man or statesman of Cambodia."

Joseph Matthews, a senior professor at the BELTEI International University in Phnom Penh, agreed that Hun Manet is Cambodia's best young leader and well educated with the knowledge of military and economic doctrines.

"These will come in handy when he takes up the premiership on Aug. 22," he told Xinhua. "There is no iota of doubt in my mind that he will be more vibrant, energetic and intelligent than his predecessors."