Seoul, Jul 15 (IANS): South Korea's defence authorities approved a 3.94 trillion-won (US$2.97 billion) plan on Friday to deploy some 20 additional F-35A radar-evading fighters by 2028 as part of efforts to counter North Korea's nuclear and missile threats.

The Defence Project Promotion Committee endorsed the "basic" procurement plan, which is subject to adjustments following a feasibility study and other procedures, according to the Defence Acquisition Programme Administration (DAPA).

The plan came after South Korea completed the deployment of 40 F-35As in January under the country's first project to procure the stealth fighter manufactured by the US defence giant Lockheed Martin, Yonhap news agency reported.

DAPA said it expects the project to minimise the "defence vacuum" that could emerge as aging fighters are decommissioned. The agency also said a "core asset" to the Kill Chain program will be added to deter possible nuclear and ballistic missile threats from North Korea.

Kill Chain refers to the country's preemptive strike programme to be mobilised in a contingency.

The committee also approved a 1.4 trillion-won project to deploy 18 CH-47F Chinook helicopters manufactured by the US firm Boeing by 2028. The project is designed to replace the aging fleet of CH-47D helicopters.