SEOUL, South Korea — President Park Geun-hye of South Korea warned on Monday that there would be more provocations from North Korea after the North’s fifth nuclear test last week, adding that they could raise the danger of war on the Korean Peninsula.

Ms. Park issued the warning when she met the leaders of opposition political parties to appeal for a united front against what she called the North’s “maniacal obsession” with building a nuclear arsenal.

Ms. Park has become increasingly critical of the North since the test on Friday, when she said that its leader, Kim Jong-un, was guilty of “fanatical recklessness” and that “his mental condition should be considered out of control.”

On Monday, she ruled out dialogue with the country, saying that its nuclear program was “not a bargaining chip” but a “present and urgent threat” to her country’s security. She said such discussions would only buy the North more time to perfect its nuclear weapons. China, Russia and opposition parties in South Korea called for talks with North Korea, insisting that sanctions alone could not end its nuclear ambitions.