TAIPEI (Reuters) - Taiwan's defence ministry said on Friday it was aiming for delivery of the first new F-16V fighter jets by the end of this year, blaming "acute fluctuations" in the international situation for delays in the island receiving them.

The United States in 2019 approved an $8 billion sale of Lockheed Martin F-16 fighter jets to Taiwan, a deal that would take the island's F-16 fleet to more than 200 jets, the largest in Asia, to strengthen its defences in the face of a stepped up threat from China, which views Taiwan as its own.

Taiwan has been converting 141 F-16A/B jets into the F-16V type and has ordered 66 new F-16Vs, which have advanced avionics, weapons and radar systems to better face down the Chinese air force, including its J-20 stealth fighter.

But Taiwan has complained of delays for the new F-16Vs, saying problems include software issues.

In an update on the deliveries, Taiwan's defence ministry said the first batch of new F-16Vs was meant to have been sent in the third quarter of this year.

"Because of acute fluctuations in the international situation, which have resulted in a compound impact such as delays in deliveries of some suppliers and adjustments to the U.S. assembly schedule, there has been a partial adjustment in when they will leave the factory," it said in a statement.

The ministry will "strive to complete the shipment of the first aircraft in the fourth quarter".

The air force will keep a close watch on the production schedule and make factory visits with the aim to have the deliveries completed by the end of 2026, it added.

Lockheed Martin ( LMT ) did not immediately respond to a request for comment.

Taiwan has reported delays to U.S. weapons deliveries such as Stinger anti-aircraft missiles since 2022, as manufacturers give supplies to Ukraine to help it battle Russian forces, and the issue has concerned U.S. lawmakers.

Taiwan's air force is well-trained but some of its fighter jets are aging, including its French-made fleet of Mirage 2000s first received in 1997. One crashed into the sea this week during a training exercise.

The air force has repeatedly scrambled to see off Chinese military aircraft flying near the island in the past five years.

Taiwan's government rejects China's sovereignty claims.