With growing fears that the brash-talking US President Donald Trump could provoke North Korea when he visits Seoul tomorrow, experts have urged the South Korean government to seek clarification on US policy towards Pyongyang and prevent any miscalculation that could light the fuse of war.

There are also worries that North Korea, which has ruled out talks to abandon nuclear weapons, could launch a ballistic missile while Mr Trump is here.

The United States President, who has previously traded insults and threats with North Korean leader Kim Jong Un, is set to visit the new US military base, Camp Humphreys, in Pyeongtaek tomorrow.

This will be followed by a meeting with South Korean President Moon Jae In and a joint press conference. Mr Moon will host a state banquet featuring K-pop performances to welcome Mr Trump, whose state visit to South Korea is the first in 25 years by a US president.

All eyes will be on Mr Trump when he speaks at South Korea's National Assembly on Wednesday. This is a rare opportunity for him to directly address the North Korean issue, which will dominate his Asia tour, although observers fear he might say something provocative that could push the region to the brink of war.

Sogang University's international relations professor Kim Jae Chun hopes that both Mr Trump and Mr Kim would "exercise caution" and refrain from ratcheting up tensions. He said: "A lot of Koreans are worried about the strong rhetoric coming from Trump. He will stand firm against North Korea and issue warnings against provocations from Kim Jong Un, but I think he will scale down on his hostile, war-like rhetoric... as a sign of goodwill to South Korea."

It is also crucial for both the US and South Korea to iron out differences in their approach towards North Korea, said Prof Kim, adding that Washington is worried about Seoul leaning towards appeasement while Seoul fears that Washington favours military action.

Incidentally, a group of US lawmakers recently urged Mr Trump to stop making provocative statements, citing a Pentagon letter dated Oct 27 which states that there are "no good military options for North Korea".

The Pentagon, giving a war assessment in response to a question from lawmakers, said a ground invasion is the only way to remove North Korea's nuclear weapons buried deeply in underground facilities "with complete certainty". But this could trigger North Korea to retaliate using biological and chemical weapons, with serious ramifications.

In the run-up to the visit, there have been rallies in South Korea, with civil groups both welcoming Mr Trump and protesting against him.

Yesterday, presidential spokesman Park Soo Hyun urged South Koreans to join the government in "warmly welcoming" Mr Trump so his state visit can serve to elevate US-Korea ties to a "great alliance".

Noting North Korea's repeated missile provocations and nuclear tests, Mr Park said a good state visit with positive results can "ultimately bring peace and prosperity to the Korean peninsula".

As for North Korea, Prof Kim said the regime would probably not carry out any provocations as it would be "too much of a risk" while Mr Trump is in the region.

Agreeing, Dr Choi Kang of the Asan Institute for Policy Studies think-tank said North Korea will probably "wait and see", and conduct a missile test only after Mr Trump's departure. This would send the message that Pyongyang will not give up nuclear weapons, he added.

Mr Trump will spend only about 24 hours in South Korea - the shortest leg of his Asian tour. He will visit the National Cemetery in Seoul on Wednesday, before flying off to China.