Seoul (AsiaNews) - For Barack Obama, the North Korean problem is "the most destabilising, dangerous situation in all of the Asia-Pacific region". Nevertheless, "The US and South Korea stand shoulder to shoulder, both in face of Pyongyang's provocations," said the US leader after holding talks with South Korean President Park Geun-hye.
The US leader is in the Korean Peninsula, one of the stops on an Asian tour that, after Japan and Korea, will take him to Malaysia and the Philippines.
Speaking at press conference in Seoul, Mr Obama said provocations by Pyongyang would only lead to further isolation.
"The US and South Korea stand shoulder to shoulder, both in face of Pyongyang's provocations and our refusal to accept a nuclear North Korea."
He said he was encouraged that China, North Korea's political mentor, was beginning to recognise that Pyongyang was "not just a nuisance but a significant problem to their own security".
Without mentioning the latter directly, the US president talked about the possibility that the North might be preparing a fourth nuclear test.
In light of "what we expect to be further provocations", Obama and Ms Park agreed to look for additional ways to apply pressure on Pyongyang.
The US leader also expressed his condolences over last week's disaster when the Sewol passenger ferry sank off South Korea.
"I am a father of two daughters close to the same age of those who were lost. I can only imagine what those parents are going through," he said.
As a token of his feelings, Obama presented a magnolia to the students' high school to commemorate "the beautiful lives lost".