SEOUL, SOUTH KOREA - South Korea may buy four spy satellites over the next decade to monitor North Korea, the defence ministry said Wednesday.

'Our ministry has been considering it but no decision has been made yet on who will be involved and details have yet to be fixed,' a spokesman told AFP.

He was commenting on a media report that said the ministry would forge technological cooperation with countries including Germany to secure the satellites.

South Korean newspaper Dong-A Ilbo, quoting what it said was an internal ministry document, reported that the military plans to spend 600-700 billion won (S$0.66- 0.77 million dollars) by 2020 to buy four spy satellites.

The ministry reportedly said Korea could acquire them relatively cheaply before 2020 if it joins forces with nations such as Germany, which have already developed spy satellites.

The ministry said its own multipurpose satellites, either in space or ready for launch, are unsuitable for military activities since they were developed for the private sector.

The United States, which bases 28,500 troops in South Korea, provides some satellite intelligence on the hardline communist North to its ally.