WASHINGTON, April 26 (Xinhua) -- The U.S. State Department on Tuesday warned that it would consider "other options" if Pyongyang continues its nuclear and ballistic missile tests.

"We call on North Korea to refrain from actions that further destabilize the region and focus on what it needs to do, which is take concrete steps toward fulfilling its commitments and its obligations to denuclearize," State Department spokesman Mark Toner told a daily press briefing.

He warned that Washington will "look at other options as we move forward if North Korea continues with this kind of behavior."

However, Toner declined to specify the options the United States is considering, only saying that Washington wants to ensure the security and safety of its allies and protect the peninsula, but also to make every effort to bring Pyongyang back to the negotiating table.

Also on Tuesday, White House spokesman Josh Earnest issued a similar warning. "We're going to continue to ramp up the pressure on the North Korean regime," Earnest told a press briefing.

Pyongyang must choose to rejoin the international community by committing to denuclearize the Korean Peninsula and come into compliance with their international obligations, he said.

In a CBS interview aired Tuesday, U.S. President Barack Obama described the DPRK as "a massive challenge."

He defended the deployment of the Terminal High Altitude Area Defense missile system on the Korean Peninsula, saying that "so that even as we try to resolve the underlying problem of nuclear development inside of North Korea, we're also setting up a shield that can at least block the relatively low-level threats that they're posing right now."

China and Russia are opposed to the possible deployment of the missile system, which they believe will create a real threat to their security and the stability in Northeast Asia.