Vietnamese soldiers attend a ceremony in Hanoi, 2019. Photo by AFP/Hoang Dinh Nam. 

Vietnam jumped one spot to 22nd in the 2020 Military Strength Ranking by U.S. website Global Firepower. 

The website ranks the military strength of 138 countries and territories based on 50 factors across eight pillars - manpower, airpower, land forces, naval forces, natural resources, geographical features, finances and logistics.

A perfect score in the index is 0, and the closer a country is to this number, the more powerful its military.

Vietnam remains the second strongest military power in Southeast Asia, with its score reducing from 0.3988 to 0.3559 this year, behind Indonesia, which is 16th strongest at 0.2544.

Thailand is in 23rd place, followed by Myanmar (35th), Malaysia (44th), the Philippines (48th), Singapore (51st), Cambodia (107th), and Laos (131st).

Cambodia and Laos are the only two countries in Southeast Asia to see its rankings drop.

The report said Vietnam has 25 attack helicopters, placing it 23rd in this category, while its combat tanks strength of 2,615 is ranked 10th.

Its naval strength, with 65 ships, places it in 35th position.

The country's annual defense budget rose to around $5.5 billion from $3.3 billion in the previous report.

Vietnam, with a population of over 97 million, has 5.48 million military personnel, including 482,000 active personnel, the ninth highest in the world.

Some 1.65 million people reach military age every year. Compulsory enlistment has existed in the country since the end of the Vietnam War in 1975, and thousands of young people join the army every spring. Men aged between 18 and 27 have to serve two years, while for women it is voluntary.

The U.S. retains its top position with 0.0606 points, followed by Russia, China, India, and Japan.

The bottom three are Somalia, Liberia and Bhutan.