In a historic first, US and Chinese troops are participating in a joint military exercise organised by the Brazilian Armed Forces, according to Brazil's navy, South China Morning Post reported.

"Operation Formosa," one of Latin America's largest military drills held annually since 1988, commenced on September 4 near the city of Formosa in Brazil.

The drills, involving about 3,000 military personnel, are scheduled to continue until September 10.

The Brazilian defence ministry clarified that the operation is unrelated to Taiwan, which officially went by the same name in 1895.

This year marks a significant milestone with both the US and China sending active military personnel, with the US contributing 54 Navy troops and China 33 members of its Navy.

In 2023, the US sent troops from its Southern Command, and China participated only as an observer.

Military contingents from Argentina, France, Italy, Mexico, Nigeria, Pakistan, the Republic of Congo, and South Africa are also involved in the drills.

"It is customary to invite friendly nations to participate in these exercises," the Brazilian Navy said in a statement.

"The importance of such invitations is directly linked to the opportunity to promote greater integration between the Brazilian Navy and the forces of friendly nations."

Brazil's defence ministry said the exercises aim to simulate amphibious operations, including warship attacks on hostile coastal regions and beach landings.

According to the ministry, live ammunition will be used in all weapons, facilitating interoperability and integration of naval, army, and air force units, as well as promoting the exchange of experiences with allied forces from other countries.

This joint participation is notable as the Chinese and American militaries have not held joint exercises since 2016 when China last participated in the US-led Rim of the Pacific Exercise (Rimpac), a group the country was excluded from due to concerns over its activities in the South China Sea.

The most recent Rimpac took place in July this year, with China again excluded due to Beijing's "reluctance to adhere to international rules or norms and standards," according to US Navy Vice-Admiral John Wade.

The inclusion of Chinese troops in Operation Formosa represents an expansion of military cooperation between Beijing and Brasilia, following several years of increased collaboration.

In 2015, Chinese troops were invited to train at Brazil's Jungle Warfare Training Centre in Manaus, a collaboration which was later extended to the Brazilian Peace Operations Joint Training Centre, which hosted Chinese students in 2017.

Last year, officers from the PLA Navy travelled to Rio de Janeiro and Brasilia for talks with their Brazilian counterparts.

In July, General Tomas Miguel Ribeiro Paiva, commander of the Brazilian army, visited Beijing to "strengthen cooperation in academic affairs" and explore "collaborations in the fields of science, technology and defence industry," according to Estadao.

Likewise, as the US Embassy in Brasilia stated, "The US and Brazil share a long-standing and multifaceted security cooperation partnership that plays a significant role in promoting regional stability and addressing common security challenges in the Western Hemisphere."

As tensions between the US and China persist in other arenas, this Brazilian-led exercise provides a rare opportunity for troops from both nations to train alongside each other in a neutral setting.