Now South Korea has partially suspended a military agreement with North Korea after Pyong-Yang successfully put its first spy satellite into space. The agreement reached in 2018 was designed to reduce military tensions. South Korea said it would also resume surveillance activities previously suspended near the border with North Korea. The UN Secretary General, Antonio Guiterres, has joined the US in defending North Korea over the launch. We can go live now to our correspondent in Seoul, Jean McKenzie. Jean, what is the impact of South Korea partially pulling out of this military agreement with the North?

What it means is that South Korea is no longer going to follow some of the rules that were set by this pact. So this pact was established back in 2018 after a period of particularly high tension here on the Peninsula. So it was signed between Kim-Jong-un and the former South Korean President, Mun-Ja-e. And what it did essentially was prohibit both militaries from doing certain activities up along the border. So it created a no-fly zone, for example, which meant that the both sides couldn't send planes up along the border. But South Korea has been saying for a while now that this means that it is vulnerable to a North Korean attack because it can't properly survey what North Korea is doing. So with this spy satellite going into space today from the North Korean side, which can, in theory, if it works, works, be able to monitor South Korean and US troops on the ground here on the Peninsula, South Korea is just saying, Look, it's now too vulnerable. It is too constrained. So by suspending parts of this pact, it is now going to fly reconnaissance planes and reconnaissance drones up along the border to say, it says, to give it a better view of North Korea and to be able to monitor an incoming attack.

And Jean, just explain a bit more about this spy satellite, because North Korea has made several attempts to get it up into space. And do we know whether it was actually successful, definitively successful? You're right.

This is now its third attempt this year. So it tried once in May and once in August, and both of those attempts failed. Now, North Korea is saying that, yes, this is a success. The US and South Korea are saying it's just too early to tell. They don't know whether it's properly gone into orbit and crucially, whether it has the right capabilities to be able to really do the military reconnaissance work that's needed to be effective. For example, is the camera high enough resolution to be able to take the images that it needs? But the South Korean officials today are saying that the reason that North Korea has succeeded on this third attempt is because it has had technological help from Russia to overcome some of the obstacles that it was struggling with in the past. Now, there is some debate over this. I've spoken to some military experts today who say that actually they think the time frame on this doesn't quite add up, because we're mapping this back to when Kim-Jong-un met Vladimir Putin in Russia's Far East a couple of months ago, and the experts are saying this just wouldn't have given the North Koreans time.

This is a piece of equipment they've been working on their own now for many years.

Thank you very much. Our correspondents there in Seoul, Jean McKenzie, thank you for that analysis.