United States does not have a diplomatic relationship with North Korea, but has appointed Sweden as its "protecting power" in the country. Sweden was the first western power to open an embassy in Pyongyang, and acts as a protecting power also for the UK and Australia.
This gives Sweden an unique role to play when it comes to dialogue and contacts in the region, said Foreign Minister Wallström.
"If we see that there is anything we can do, we will do so," Wallström told the news agency TT.
Several countries have expressed concern over the harsh words between the US and North Korea. Now Sweden's Wallström also urges the parties to cool it.
"You end up in a situation, where it gets harder to back down. The more you go for it, the harder it becomes to not lose face when you choose another route than the route of violence. And on top of that, the risk of mistakes or misjudgements increases," she said.