American automaker General Motors said it will expand the recall of Chevy Bolt electric vehicles equipped with South Korean supplier LG's batteries over fire risks, which is expected to additionally cost about US$1 billion.

The latest recall covers 73,000 Bolt EVs and EUVs from model years 2019 through 2022 sold in the United States and Canada to replace the defective battery modules.

It is on top of about 69,000 Bolt EVs from 2017-2019 model years included in the previous recall in July over the same issue, which cost about $800 million.

"In rare circumstances, the batteries supplied to GM for these vehicles may have two manufacturing defects -- a torn anode tab and folded separator -- present in the same battery cell, which increases the risk of fire," GM said in a statement.

GM said it will pursue reimbursment from LG after further investigation, saying it has discovered manufacturing defects in certain battery cells beyond the Ochang plant in South Korea.

LG Energy Solution operates a battery factory in Michigan, while its joint venture with GM, Ultium Cells, has been building another facility in Ohio, with plans to open another in Tennessee.

LG said it has been actively working with its client and partners to ensure that the recall measures are carried out smoothly.

LG Electronics has supplied GM with battery modules that are made with battery cells from LG Chem's wholly owned subsidiary, LG Energy Solution.

"The reserves and ratio of cost to the recall will be decided depending on the result of the joint investigation looking into the root cause, currently being held by GM, LG Electronics and LG Energy Solution," LG said referring to its subsidiaries.

Earlier this month, LG Electronics set aside 234.6 billion won as a provision expense for the Bolt EV recall, while LG Chem earmarked 91 billion won.

The recalls are a blow to GM's plan to go all-electric by 2035 and to LG Energy Solution, which is preparing to go public on the Seoul bourse later this year. (Yonhap)