Both the US and North Korea have an agreement on this, but at issue is the scope of sanctions to be eased or lifted and the preconditions for that, according to the president.

He said his administration's push for joint ventures with the North has made little progress due to the UN Security Council sanctions.

But there are some inter-Korean projects not subject to sanctions, such as individual tours, he added, apparently referring to the suspended tours by South Koreans at Mount Kumgang on the North's east coast.

Moon has already put forward various proposals for improving inter-Korean relations and creating the conditions for leader Kim Jong-un to visit the South.

He said Washington also needs to present "new ideas" to break the stalemate in denuclearization talks in close cooperation with Seoul.

Moon said there is not much time left as the US is drawing nearer to November's presidential polls.

He nonetheless emphasized that it is too early to be gloomy about the future of the Korea peace process.

"I think we are not for now at the stage of being pessimistic about South-North dialogue and North Korea-US dialogue, although it's not a stage be optimistic," he said.

He mentioned President Donald Trump's birthday greetings to the North Korean leader, which were sent in a personal letter, describing the message as a token of a close personal relationship that is still alive.

Even if dialogue between Pyongyang and Washington is not active, Trump and Kim maintain their mutual trust and efforts for the resumption of talks are under way, Moon added.

He also said the government is continuing a push to expand inter-Korean cooperation and there is an "optimistic prospect" of progress. (Yonhap)