WASHINGTON, Oct 10 (Reuters) - A senior U.S. administration official on Saturday called North Korea's display of a previously unseen intercontinental ballistic missile "disappointing" and called on the government to negotiate to achieve a complete denuclearization.

Analysts said the missile, which was shown on a transporter vehicle with 11 axles, would be one of the largest road-mobile intercontinental ballistic missiles (ICBMs) in the world if it becomes operational.

"It is disappointing to see the DPRK continuing to prioritize its prohibited nuclear and ballistic missile program over working towards a brighter future for the North Korean people," the official said. "The United States... calls on the DPRK to engage in sustained and substantive negotiations to achieve complete denuclearization."

(Reporting by Andrea Shalal, Editing by Rosalba O'Brien)