PYONGYANG, Oct. 3 (Xinhua) -- The Democratic People's Republic of Korea (DPRK) succeeded in test-firing a new type of submarine-launched ballistic missile (SLBM) on Wednesday morning, the official Korean Central News Agency reported on Thursday.

The Academy of Defense Science fired the new-type ballistic missile, known as Pukguksong-3, in vertical mode in the waters off the county's eastern Wonsan Bay, the report said.

"The test-firing scientifically and technically confirmed the key tactical and technical indexes of the newly-designed ballistic missile and had no adverse impact on the security of neighboring countries," it added.

Top DPRK leader Kim Jong Un did not guide the test-firing personally but sent warm congratulations on behalf of the Central Committee of the ruling Workers' Party of Korea to the research units involved in the test-firing, the report said.

The successful test-firing is of great significance as it "ushered in a new phase in containing the outside forces' threat to the DPRK and further bolstering its military muscle for self-defence," it said.

The launch came a day after the DPRK's Vice Foreign Minister Choe Son Hui said Pyongyang and Washington had agreed to hold working-level talks later this week.

U.S. State Department spokesperson Morgan Ortagus later confirmed the talks, which she said would happen "within the next week."

Negotiations between the two countries have been deadlocked since a second summit between Kim and U.S. President Donald Trump in February ended without a deal.