SEOUL, South Korea, Dec. 11 (UPI) -- A bridge between China and North Korea has been closed temporarily, Kyodo News reported.
The Sino-Korean Friendship Bridge stretches about a half-mile across the Yalu River connecting the North Korean city of Sinuiju to Dandong city in China.
The road-and-rail bridge is said to be the economic lifeline for the North, connecting more than 70 percent of its trade with China, according to Hankyoreh.
Beijing's foreign ministry announced last month that the bridge would be closed soon for maintenance purposes sometime in December.
However, the closure has added to growing speculation that China is taking a tougher stance against the reclusive state.
A source based in China told TV Chosun, "UN Security Council resolution 2375 adopted in September bans exports of fabric and clothing from North Korea but there was a 90-day grace period, which ended on Dec. 10, so the repair works have begun."
Many have expressed suspicion over the timing of the move, noting that repairs should be made in spring or summer, rather than winter, SBS reported.
Observers have also suggested Beijing is showing discontent over what was seen as a diplomatic snub of a Chinese envoy last month.
Song Tao's four-day trip to Pyongyang, commissioned by President Xi Jinping, ended without a reported meeting with regime leader Kim Jong Un. This was followed by an indefinite suspension of Air China flights to Pyongyang.
Although Air China said its decision was made due to a fall in demand, some experts believe it was a politically motivated move.
"When Xi Jinping's envoy went to the North, Kim Jong Un didn't come out to meet him, so China is angry because they lost face," a source told TV Chosun.
China is issuing a warning that the North will hit a critical situation if it doesn't keep in step with Beijing, according to Kang Jun-young, professor of International and Area Studies at Hankuk University of Foreign Studies.
"Another part of it is that China would lose face in the international community if it cannot mediate the North Korea nuclear crisis so it is showing that it is diligently enforcing international sanctions," Kang said.