An inconspicuous sentence in the China-Russia joint statement issued after last week’s summit referred to North Korea’s role in allowing Chinese vessels to sail on the Tumen River, underlining an overlooked area for trilateral cooperation that could give Beijing easier access to the sea.

The statement by Russian leader Vladimir Putin and his Chinese counterpart Xi Jinping only mentioned the DPRK twice, the first time to warn the U.S. against “intimidating” Pyongyang through military exercises on and around the Korean Peninsula.