The United States's top envoy for North Korea held phone talks with his Chinese counterpart on Tuesday.

According to the Chinese Foreign Ministry, China's Special Representative on the Korean Peninsula, Liu Xiaoming, spoke by phone with U.S. Special Representative Sung Kim and that the two agreed to keep in contact.

Liu outlined China's position on matters involving the Korean Peninsula and reiterated the need to pursue denuclearization of the peninsula and negotiations between the U.S. and North Korea at the same time. 

The Chinese envoy also stressed that such issues should be resolved based on a "phased and synchronized" principle. 

The U.S. State Department confirmed that the call took place but did not elaborate further. 

Department spokesperson Ned Price said in a briefing on Tuesday that the North's nuclear weapons and ballistic missile programs are not challenges that the U.S. can tackle alone.

Stressing the need for the U.S. to cooperate with its allies South Korea and Japan, Price added that China has a role to play as well vis-à-vis its influence on North Korea.