"We've seen, you know, no outward indications [of a test launch], but that doesn't tell you much," Panetta told reporters during a joint briefing with Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey at the Pentagon.
North Korea recently claimed the country's military was poised to conduct a new round of long-range, ballistic missile and weapons tests, a flagrant violation of United Nations mandates.
The tests, according to the country's National Defense Commission, headed by North Korean leader Kim Jong Un, will include launches of "a variety of satellites and long-range rockets" as well as a "nuclear test of [a] higher level" compared to previous ballistic weapons drills conducted by the country in the past.
This latest round of testing is part of the country's preparation for an "upcoming all-out action [that] ... will target the U.S., the sworn enemy of the [North] Korean people," according to the commission's statement.
Those threats were reportedly in response to a recent U.N. decision to expand sanctions against North Korea, intended to punish the Asian nation for continuing its nuclear weapons development program.
While questions remain on whether Pyongyang has the ability to conduct the proposed weapons tests, the threat of those tests has been a "needlessly provocative" action that has set back efforts to convince North Korea to joint the international community, Panetta said.
"We've made very clear to the North Koreans they have a choice. They have a choice between trying to become a member of the international family ... [doing] what they can to improve the status of their people or to engage in this kind of provocative behavior," Panetta said, echoing comments by White House press secretary Jay Carney on Thursday.
Threatening to test launch ballistic missiles or other weapons will "in the end will do nothing ... other than jeopardize the hope for peace," in the Asia-Pacific region, Panetta added.
Pacific Command has intelligence and surveillance assets in place to monitor the launch, should Pyongyang follow through with the weapons drill, Adm. Samuel Lockear said last year. The four-star admiral declined to go into specifics regarding what U.S. assets were in place within the region to track the proposed test launch.