In 2022, the two countries signed a $13.7 billion arms deal -- Seoul's largest to date -- which included South Korean K2 tanks and fighter jets for Poland, Ukraine's ally and neighbour.

The negotiations for the potential upcoming deal -- part of the broader 2022 agreement -- are "in the final stages, with both governments and companies working to expedite its conclusion", an official from South Korea's Defense Acquisition Program Administration told AFP.

While the agency did not disclose the amount, it said if signed, the deal would be the "largest ever based on a single weapon system".

South Korea's Yonhap news agency reported that the potential deal is worth around $6 billion, with the country's Hyundai Rotem set to manufacture 117 tanks and Poland's state-owned Polish Armaments Group producing 63 locally.

Yonhap reported that the signing ceremony is scheduled to take place in late June in Poland, but the Defense Acquisition Program Administration said the "signing schedule for the second contract has not yet been finalised".

"This contract includes provisions such as local production and technology transfer, which have required a significant negotiation period," it said in a statement.

The contract was originally expected to be signed late last year, according to Yonhap, but was delayed due to issues including political turmoil in South Korea following the brief declaration of martial law in December.

South Korea has emerged as a major player in global defence exports, as Moscow's invasion of Ukraine created opportunities for its industry to secure large-scale contracts across Europe and the Middle East.

It has signed major arms deals with countries such as Poland and Romania, including the export of K9 Howitzers and Chunmoo missile systems.

South Korea's President Lee Jae-myung, who took office last week, has vowed a more dovish approach towards Pyongyang -- an ally of Russia -- compared with his predecessor Yoon Suk Yeol.

The nuclear-armed North, which technically remains at war with the South, has recently bolstered military ties with Russia.

Pyongyang sent at least 14,000 troops to support Moscow's war in Ukraine, and officially declared the South an enemy state.