Vice foreign ministers from South Korea and the United States held a phone conversation on Friday to discuss Russian President Vladimir Putin's expected trip to North Korea next week and other alliance, regional and global issues.

According to Seoul's foreign ministry, first vice foreign minister Kim Hong-kyun said Putin's trip must not help enhance Pyongyang and Moscow's military cooperation that violates UN Security Council resolutions and undermines regional peace and stability.

Expressing Washington's full support behind Seoul's position, U.S. Deputy Secretary of State Kurt Campbell said the U.S. deeply sympathizes with concerns over regional instability and challenges, suggesting that the allies continue their close cooperation.

The two vice ministers also agreed to keep monitoring the situation, while preparing a coordinated stern response to the North's provocations against the South or acts that serve to heighten tensions in the region.

Taking up on North Korean leader Kim Jong-un's invitation to visit his country last September, Putin is expected to make a reciprocal trip to Pyongyang early next week, where the two sides could seek ways to further bolster their military cooperation.