China is weighing options to buy Russia's new Sukhoi Su-57 stealth fighter jet as Moscow has identified China and India as potential customers to acquire its advanced warplane.

Described by Russian President Vladimir Putin as "the world's best military plane", the Su-57 is a fifth-generation multi-role fighter jet capable of both aerial combat and hitting the ground and naval targets.

Viktor Kladov, director of international cooperation and regional policy at Russia's Rostec defence industrial holding company at a briefing at the Langkawi International Maritime and Aerospace Exhibition in Malaysia identified India and China as potential buyers, state-run Global Times reported on Monday.

The Chinese air force, which currently has a range of homegrown new aircraft including the stealth fighter J-20, besides Russia's Su 35s, is keeping a close eye on India's acquisition of France's Rafale plane adding a new strategic dimension to its air assets.

While China has been developing its own new generation military aircraft, it is still heavily reliant on Russian engines for the planes as it is yet to produce a reliant engine of its own. Both China and Pakistan rely on Russian engines for their jointly produced JF-17 Thunder.

Chinese defence analyst Wang Ya'nan, the chief editor of Aerospace Knowledge, said Russia's offer to sell SU-57 is more attractive to India as China has its stealth fighter.

Unlike China, India does not have a fifth-generation fighter, so the Su-57 is an attractive warplane to India, he told Global Times.

Wang said although he is convinced of the Su-57's capabilities, he is less keen to see China buy it because China has already developed its own fifth-generation fighter jet J-20.

Kladov said Su-57E, an export version of the Su-57, is expected to receive export approval from Putin in a few weeks.

Naming China as a potential customer, he said, "China has recently taken delivery of 24 Su-35 aircraft, and in the next two years will make a decision to either procure additional Su-35s, build the Su-35 in China, or buy a fifth-generation fighter aircraft, which could be another opportunity for the Su-57E."

Xu Guangyu, a senior consultant at the China Arms Control and Disarmament Association, told the Global Times that it is possible that China could make the purchase because China needs to study from other countries' strengths whenever possible.

"Kladov's remarks are also an indication of cooperation in high-end military technology under the framework of the two countries' strategic cooperation," Xu said.

Wang Yongqing, the chief designer of the Shenyang Aircraft Design Institute under the state-owned Aviation Industry Corporation of China, wrote in the February 2019 issue of Aerospace Knowledge magazine that the Su-57 is designed to have strong supersonic cruise capability and super-manoeuvrability, and intentionally reduces stealth, a capability said to be crucial to a fifth-generation fighter, to a secondary priority.

While US warplanes stress stealth and beyond visual range attacks, the Su-57 can evade incoming long-range missiles through its super-manoeuvrability and engage enemies at close range, a situation where stealth is not so important as super-manoeuvrability, Wang said.

However, Chinese defence analyst Wang said China is perfecting its own fifth-generation technology as the J-20 is on the way to being mass produced. During this period, integrating another fighter jet into the fleet could bring challenges to the integration of the Chinese military's weapons and equipment systems and disrupt development and training plans, he said.

He noted that a technical study is possible, using the Su-57 in the Chinese military is unlikely.

The Su-57 could also become a strong market competitor to the Chinese FC-31 stealth fighter jet, Weihutang, a column affiliated with China Central Television (CCTV), reported on Friday, noting that the FC-31 and the US' F-35 are the only two current fifth-generation fighter jets available on the international market.