Labor leader Bill Shorten will meet with the South Korean prime minister during a four-day trip which will also includes security talks in Japan.
Mr Shorten and foreign affairs spokeswoman Penny Wong will head to the global security hotspot on Sunday.
"Today, we commence a four-day visit to the Republic of Korea and Japan to demonstrate our bipartisan commitment to both nations and highlight the strategic importance a future Labor government will place on our relationships in North Asia," Mr Shorten said ahead of the trip.
The agenda includes meetings with Korean Prime Minister Lee Nak-yeon, former Secretary-General of the United Nations Ban Ki-Moon, Commander US Forces Korea, General Vincent K Brooks and the Foreign Minister of Japan Taro Kono.
US President Donald Trump has signed an executive order boosting his country's ability to sanction foreign banks, individuals and companies that facilitate trade with North Korea, which is ignoring calls to stop nuclear tests.
Responding to Mr Trump's address at the UN, in which he threatened to "totally destroy" North Korea if it attacked the US or its allies, Kim Jong-un issued a statement describing the speech as "unprecedented rude nonsense".
He said Mr Trump would "pay dearly" and after his "ferocious declaration" of war, North Korea would consider a "corresponding, highest level of hard-line countermeasure".
Mr Shorten said the region faced an "unprecedented crisis".
"The threat posed by North Korea has an immediate impact on the security of its neighbours, and on global peace and security," he said.
"It is essential that we work with South Korea and Japan, with other regional allies and partners, and with the broader international community to encourage and persuade North Korea to adhere to UN Security Council resolutions."
He said bilateral relations with Japan were deep.
"Our visit will demonstrate our bipartisan support for the Republic of Korea and Japan, and demonstrate that a change of government will not affect Australia's strong support for both nations at this dangerous and challenging time."
