SEOUL: South Korean President Park Geun-hye held telephone calls with US President Barack Obama and Japanese Prime Minister Shinzo Abe on Tuesday and agreed to work for 'strong and effective' UN Security Council sanctions against North Korea following its weekend rocket launch. Park and Obama also agreed various sanctions outside the UN are needed to sanction and punish North Korea after its rocket launch on Sunday, Park's office said in a statement. Obama called the launch a direct threat to the security of the United States and its allies, Park's Blue House office said.