A U.S. senator has urged the United States to "resume the sanctions regime" against North Korea and to engage China in efforts to deal with Pyongyang.

Democratic Senator Robert Menendez, a ranking member of the Senate Foreign Relations Committee, made the call during an interview with CNN on Thursday. 

When asked how he would advise U.S. President Donald Trump if North Korea conducts a nuclear test, Menendez said that the U.S. should resume the sanctions regime and "engage China vigorously" because China is likely the key to inducing a successful outcome with North Korea.

The senator criticized the cancellation of military exercises between the U.S. and South Korea, calling it an "enormous gift" to North Korean leader Kim Jong-un. 

He also accused Trump of weakening the sanctions regime against North Korea because "people think that we're engaged with North Korea."