Top South Korean and US officials held telephone talks on Tuesday to discuss stronger bilateral alliance and North Korea’s nuclear programme, Seoul’s Foreign Ministry said.

South Korean Foreign Minister Yun Byung-se spoke to US Secretary of State Rex Tillerson for 25 minutes, Xinhua news agency reported.

Citing a series of senior-level phone talks between the two allies, Minister Yun highly appreciated the importance the Trump administration placed on the bilateral alliance.

The two officials agreed to strengthen the US-South Korea relations to the strongest ever under the Trump administration to effectively tackle North Korea’s nuclear programme and other relevant issues.

The South Korean diplomat stressed that the Pyongyang’s nuclear programme would become the most serious issue faced by the new US administration, saying the two countries should be prepared for any possible North Korean provocations.

On January 30, US President Donald Trump held phone talks with South Korean Prime Minister Hwang Kyo-ahn who is serving as acting President following the impeachment of President Park Geun-hye.

US Defence Secretary James Mattis visited South Korea last week.