The top diplomats of South Korea and the United States agreed on Sunday to push for the most powerful sanctions on North Korea during their phone discussion following its sixth nuclear test, Seoul's foreign ministry here said.

Foreign Minister Kang Kyung-wha and US Secretary of State Rex Tillerson had 25-minute talks to discuss countermeasures after North Korea earlier in the day conducted what it called a successful test of a hydrogen bomb that can be mounted onto an intercontinental ballistic missile.

Kang told Tillerson of the importance of using maximum sanctions and pressure to induce North Korea to change its behavior and come to the dialogue table, according to the Ministry of Foreign Affairs. She stressed the urgency of the efforts to prevent North Korea from realizing its goal of nuclear armament.

Kang also said Seoul will consult with the US about joint measures including a new resolution by the United Nations Security Council and the deployment of US strategic military assets in South Korea, according to the foreign ministry.

Tillerson affirmed that the US will place the strongest-ever sanctions on North Korea based on its alliance with South Korea.

Both emphasized the need to work together in taking future steps on North Korea and shared the results of their consultations with other countries on the issue.

They agreed to have further discussion in the course of bilateral and multilateral diplomatic occasions including a U.N.

General Assembly meeting scheduled for later in the month, the ministry added. (Yonhap)