SEOUL, Feb. 22 (Reuters) — South Korean President Moon Jae-in said relations with the United States are "rock solid" and "as strong and robust as ever" in a media interview, as his administration gears up for a possible summit with North Korean leader Kim Jong Un.

Moon's administration has faced questions from lawmakers over whether there have been any differences in opinion or policy between staunch allies South Korea and the United States over efforts to engage North Korea to get it to abandon its missile and nuclear programmes.

"President Trump said that I could notify him at any time if help was needed in the process of carrying out inter-Korean dialogue and that he supported me 100 percent," Moon told the magazine Monocle in an interview published on Thursday.

"My goal is to resolve the North Korean nuclear issue and solidify peace."

South Korean officials, including Foreign Minister Kang Kyung-hwa, have denied any differences with the United States and stressed that South Korea is in close negotiations with it on every step regarding North Korea policy.

South Korea held talks with North Korea for the first time in more than two years in January and agreed to host North Korean athletes, musicians, cheerleaders and a high-level delegation at the Winter Olympics being held in the South.

North Korean leader Kim Jong Un sent his younger sister, Kim Yo Jong, as part of the delegation to meet Moon. She invited the South Korean president to Pyongyang for talks with her brother.

Signs of a North-South thaw have prompted speculation about the possibility of direct U.S.-North Korea talks after months of tension and exchanges of insults between U.S. President Donald Trump and the North Korean leader fuelled fears of war.