South Korea's top diplomat says the government will have to double diplomatic efforts to achieve denuclearization and lasting peace via a "virtuous cycle" of improved inter-Korean ties and progress in denuclearization.

At the opening of an annual meeting of the heads of overseas diplomatic missions in Seoul Monday, Foreign Minister Kang Kyung-wha said the country faces a critical opportunity for resolving North Korea's nuclear issue.

She said while the journey ahead won't be smooth sailing, she has confidence in the strength of the country's diplomacy.

Kang also vowed to carry out reforms next year to increase efficiency within the diplomatic community.