(CNN) North Korea is "playing its normal game" in its negotiations about denuclearization with the United States, Sen. Jeff Merkley said Wednesday following a Senate hearing with Secretary of State Mike Pompeo.

"To claim that something new or different has occurred here -- no, North Korea is playing its normal game," the Oregon Democrat said in an interview on CNN's "Anderson Cooper 360," "in which it agreed to a concept of its own definition of denuclearization, and then freezes activity to let the heat go down."

Merkley said North Korea has previously engaged in similar behavior -- pausing nuclear tests during negotiations -- to gain temporary relief from international pressure.

"What we have right now with North Korea is the beginning of a conversation in which they have not done another nuclear test ... they haven't done another ballistic missile test," he said, "but that type of freeze is the sort of thing they have done before with other administrations. Other administrations did actually get a detailed plan worked out."

Merkley highlighted comments that Pomepo made during the hearing that revealed what Merkley characterized as his failure to reach detailed agreements with North Korea about specific aspects of denuclearization.

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