Seoul, June 24 (IANS): South Korea, the United States, and Japan on Monday condemned "in the strongest possible terms" the expanding military cooperation between Russia and North Korea, days after the signing of the two isolated states' new treaty on mutual defence aid at the leaders' summit last week.

A joint statement came after Russian President Vladimir Putin and North Korean leader Kim Jong-un signed the "comprehensive strategic partnership" treaty during Putin's visit to Pyongyang last week, Yonhap news agency reported.

The treaty calls for the provision of military and other assistance from one side to the other "with all means" at its disposal and "without delay" if either of the two gets invaded or put in a state of war.

"The United States, South Korea, and Japan condemn in the strongest possible terms deepening military cooperation between North Korea and Russia, including continued arms transfers from North Korea to Russia that prolong the suffering of the Ukrainian people, violate multiple United Nations Security Council Resolutions, and threaten stability in both Northeast Asia and Europe," the statement read.

The three countries said that the new treaty between Moscow and Pyongyang should be of "grave concern" to all concerned parties that uphold the non-proliferation regime.

They reaffirmed their commitment to strengthening cooperation to counter the threats posed by the North and prevent the escalation of the situation.

The US said that its commitment to the defence of Korea and Japan remains "ironclad."

"The United States, South Korea and Japan also reaffirm that the path to dialogue remains open and urge North Korea to cease further provocations and return to negotiations," it said.

The statement was issued under the names of Jung Pak, the US senior official for North Korea; Cho Koo-rae, the South Korean vice foreign minister; and Namazu Hiroyuki, assistant minister for Asian and Oceanian Affairs at Japan's foreign ministry.