A senior Pentagon official said Monday that South Korea has "a lot of ways" to help the U.S. missile defense system in Northeast Asia.

"Yes, there are a lot of ways one can contribute," Kathleen Hicks, principal deputy under secretary of defense for policy, said at a forum. "We do have dialogue with the (South) Koreans about how to contribute to missile defense."

She was responding to Yonhap News Agency's question on what the U.S. wants from South Korea as it bolsters missile defense in the region.

Citing radars as an example, she added, "That doesn't have to be proactive defense itself or certainly active participation through the use of missiles."

She refused to go further into details.

Cooperation on the U.S. missile defense system is a sensitive issue in South Korea as in many other nations.

Many South Koreans agree with the need to have an appropriate capability to shield their nation from North Korea's missile threats.

They are also concerned about the possibility that South Korea will be drawn into possible conflicts between the U.S. and countries in the region, including China.

Hicks did not answer a question on Seoul's pursuit of longer-range ballistic missiles.

Sources say Seoul and Washington are nearing a deal on expanding Seoul's missile range to 800 kilometers, enough to cover all of North Korea. South Korea is currently prohibited from developing ballistic missiles with the range of more than 300 km.

In a formal reply to Yonhap's inquiry on news of a pending agreement, the State Department reiterated that routine consultations are under way.

"In the context of our strategic alliance with the Republic of Korea, we regularly consult on a wide range of nonproliferation and security issues," a department official said on the customary condition of anonymity.

There is speculation that the U.S. is demanding South Korea assume a greater role in regional missile defense in return for allowing it to have longer-range ballistic missiles.

An informed source earlier said the allies have virtually completed talks on the missile range issue but want to wrap up consultations on additional issues before a formal announcement.

In the forum, hosted by Center for Strategic and International Studies (CSIS), meanwhile, former Deputy Secretary of State Richard Armitage said expanding South Korea's missile capability is "long overdue."

"My own view is that this is long overdue," he said, citing a series of North Korea's deadly provocations against the South, including the sinking of a naval ship in 2010 that led to the deaths of 46 sailors.

"North Korea has gotten away with one provocation after another. And nothing happened. There was no response. This is a response," said Armitage, who served in the George W. Bush administration.

Walter Slocombe, former under secretary of defense for policy, emphasized that missile defense is a key part of U.S. defense commitment in Northeast Asia.

"China has to understand that the Korean problem is a very serious problem," he said.

The U.S. missile defense would have "no significant impact" on China itself, he added. (Yonhap News)