The island of Taiwan is spending billions of dollars to upgrade fighter jets purchased from the US, yet they are still no match for the Chinese mainland's J-11s, mainland experts said, as the island conducted its first highway takeoff and landing drill with the F-16V at the annual Han Kuang military exercises on Tuesday.

The J-11 is not even the mainland's best fighter jet, analysts noted.

A US-made F-16V led other jets in taking off and landing on a highway in Changhua county in western Taiwan Tuesday morning as a highlight of the five-day Han Kuang live-fire exercises that started on Monday, Taipei-based The China Post reported on Wednesday.

Taiwan regional leader Tsai Ing-wen said the drill was challenging and "demonstrated the defense capability and trustworthiness of Taiwan's military," the report said.

However, Fu Qianshao, a mainland air defense expert, told the Global Times that although highway emergency takeoffs and landings could be helpful in combat, the drill is more of a temporary training rather than a regular operation.

"It would be an exaggeration to consider such contingency training as a combat capability boost," Fu said.

The drill also marked the exercise debut of the first F-16 upgraded to the "V'' configuration, featuring advanced radar and other combat capabilities, the Associated Press reported.

Taiwan's air force is spending about $4.21 billion to upgrade 144 F-16A/Bs to the F-16V, and is trying to purchase new ones from the US, the AP report said.

The F-16V is a 3.5-generation (or 4.5 generation, according to another widely used classification) jet built by the US, and while its fire control and weapons systems are improved, their contributions to the overall combat capability are limited, Fu said.

Compared to the Chinese mainland's 3.5-generation lightweight fighter jets, the J-10B and J-10C, the F-16V holds no significant advantage, Fu said, noting it is no match to the mainland's J-11 heavy fighter jet series.

China has already commissioned its fourth-generation stealth fighter jet, the J-20, which is far more advanced than any third-generation ones and comparable to the US' most advanced fighter jet, the F-22, military observers said.