(SOUNDBITE) (ENGLISH) U.S. PRESIDENT DONALD TRUMP SAYING: "Tremendous progress on North Korea." Despite President Trump's assertion that his landmark deal with North Korea is leading to denuclearization, reports released Monday by a Washington D.C.-based think tank revealed that it had identified 13 of an estimated 20 undeclared missile bases in the country that are still up and running.

And while North Korea has said its dismantled some of its sites and raised the possibility of shuttering more, the reports find it has been making improvements at some of the bases.

The Trump administration has touted great progress in its effort to eliminate North Korea's nuclear and missile program.

(SOUNDBITE) (ENGLISH) U.S. PRESIDENT DONALD TRUMP SAYING: "The relationship's very good with North Korea.

Looks like we'll have a second summit soon." But the existence of these bases, which Pyongyang denies, shows otherwise.

Analysts say that accurately revealing nuclear weapons and missile capabilities would be an important part of any denuclearization deal.

That hasn't happened yet.

In June, North Korean leader Kim Jong Un and President Trump pledged to work toward denuclearization at their landmark summit but it was an agreement short on specifics.

Earlier this year, North Korea declared it had halted its missile and bomb testing, however, the U.S. and S.

Korea have yet to demand any specifics on the size or scope of its weapons program.

And in terms of negotiations, little headway has been made.

Just last week - North Korea called off a meeting.

(SOUNDBITE) (ENGLISH) U.S. AMBASSADOR TO THE UNITED NATIONS NIKKI HALEY SAYING: North Korea said they needed to postpone.

Secretary of State Pompeo was ready to come." The sites mentioned in the reports are scattered in remote areas across the country and could be used to house ballistic missiles, with the largest believed capable of striking anywhere in the U.S.