Taiwan signaled Thursday that it had abandoned a plan to buy advanced new anti-submarine warfare helicopters from the United States, saying they were too expensive.

Taiwan had earlier said it was planning to buy 12 MH-60R anti-submarine helicopters, made by Lockheed Martin Corp LMT.N unit Sikorsky, but Taiwanese media reported that the United States had rejected the sale as not being in line with the island’s needs.

Asked in parliament about recent changes to Taiwan’s purchases of new U.S. weapons, Defense Minister Chiu Kuo-cheng mentioned the helicopter case first.

“The price is too high, beyond the scope of our country’s ability,” he said.

Two other arms purchases have also been delayed — M109A6 Medium Self-Propelled Howitzer artillery systems, and mobile Stinger anti-aircraft missiles.

The Raytheon Technologies’ RTX.N Stingers are in hot demand in Ukraine, where they have been used against Russian aircraft, but U.S. supplies have shrunk, and producing more of the anti-aircraft weapons faces significant hurdles.

Chiu said they had already signed the contract for the Stingers and paid for them, and they would press the United States to deliver them.

“We don’t view arms sales as a trifling matter, and we have backup plans,” he added, without elaborating.

Taiwan says the United States has offered its alternatives to the M109A6, including truck-based rocket launchers made by Lockheed Martin called the High Mobility Artillery Rocket System, or HIMARS.

Chiu said they were still considering their options on that.

Taiwan, claimed by China as its own territory, is undertaking a military modernization program to improve its capabilities to fend off a Chinese attack, including with precision weapons like missiles.

President Tsai Ing-wen has championed the concept of “asymmetric warfare,” which involves developing high-tech, highly mobile weapons that are hard to destroy and can deliver precision attacks.

U.S. officials have been pushing Taiwan to modernize its military so it can become a “porcupine,” hard for China to attack.

China has been ramping up its own military modernization and pressure against Taiwan as it seeks to force the democratically governed island to accept Beijing’s rule.