Japanese Foreign Minister Taro Kono urged South-east Asia not to let up its pressure on North Korea, during his visit to Singapore yesterday.
His efforts to shore up a united front against North Korea come amid a detente between Seoul and Pyongyang at the ongoing Pyeongchang Winter Games.
Countries should not be blinded by North Korea's charm offensive, said Mr Kono during a breakfast meeting with his Singapore counterpart Vivian Balakrishnan.
Both ministers also agreed to tackle the issue of ships transferring oil to North Korean vessels at sea in breach of international sanctions.
"They agreed that South-east Asia should not be allowed to be loopholes for North Korea to evade sanctions," Japan's deputy foreign ministry spokesman, Mr Toshihide Ando, told reporters after the visit.
In addition, the ministers agreed to maximise pressure on North Korea by fully implementing United Nations Security Council resolutions. They were of the view that the international community should be united in fully implementing these resolutions, said Mr Ando.
Mr Kono's visit to Singapore is the first by a Japanese foreign minister in five years.
The two foreign ministers also discussed greater cooperation between Singapore and Japan in air connectivity, innovation and digital technology, said the Ministry of Foreign Affairs (MFA) in a statement.
Japan is competing with several other countries to build the multibillion-dollar Kuala Lumpur-Singapore High Speed Rail, for which bids must be submitted by the middle of this year.
Mr Kono "conveyed Japan's interest in the project and asked for cooperation from Singapore", said Mr Ando.
The Japanese minister also called on Prime Minister Lee Hsien Loong at the Istana yesterday.
They discussed the two regional trade pacts in the works which Singapore and Japan are part of - the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP) and the Asean-led Regional Comprehensive Economic Partnership (RCEP).
PM Lee commended Japan's leadership in concluding the CPTPP talks, according to MFA. He said he looks forward to strengthening bilateral economic cooperation through a review of the Japan-Singapore Economic Partnership Agreement.
Mr Kono noted that Singapore's chairmanship of Asean this year coincides with the 45th anniversary of Asean-Japan dialogue relations. He said Japan looks forward to working closely with Singapore.
Yesterday, Mr Kono also visited the Maritime and Port Authority of Singapore's port operations control centre, where he was briefed on Singapore-Japan maritime cooperation.
Said Dr Balakrishnan on Facebook after the meeting: "Our two countries share a longstanding and close friendship, and I look forward to deepening our cooperation in the years ahead."