Prime Minister Hun Sen has congratulated the Koreas on holding joint Winter Games, welcoming the move as a step towards peace.
He also criticized other foreign powers, who he said had not supported the decision.
While the United States has appeared to endorse the engagement, it has also said sanctions against the north must be intensified to push the regime towards negotiations to end its nuclear weapons program.
In a speech to graduates in Phnom Penh, Hun Sen said Cambodia’s stance was to call for further engagement.
“When the situation is hot, [you all] jointly curse, but when it calms down, you all keep silent. But Cambodia wants to congratulate the step forwards of the two Koreas, who are brothers. The attitude shows the desire to compromise despite different political regime,” he said.
“I think all the superpower countries and not only the superpower countries should congratulate and encourage the two Koreas cooperate with each other,” he added.
Arend Zwartjes, U.S. Embassy spokesman, declined to comment.
On Monday, Mike Pence, U.S. vice president, was quoted by the Washington Post as saying that Washington was ready to engage in talks over North Korea's nuclear program.
Japan and Singapore this week agreed to cooperate to prevent North Korea from evading U.N. Security Council sanctions.
In September, Cambodia condemned North Korea’s nuclear program and called on the regime to respect U.N. Security Council resolutions to cease nuclear tests.
Paul Chambers, a lecturer at the College of ASEAN Community Studies, Naresuan University, in Thailand, said ASEAN can and should have a voice on the North Korea issue through the ASEAN Regional Forum (ARF), which has worked to diminish political tensions between Asian states in the past.
“Indeed ASEAN should now promote the resolution of the Koreas dispute through ARF, first because ARF has been successful in the past, and second because by suggesting ARF to the two parties, it advertises ASEAN as a credible facilitator of peace,” he said in an email.