Moscow on Wednesday insisted that the range of a missile system that has prompted Washington to say it will withdraw from a key Cold War arms treaty is allowed under the agreement.

Russian artillery chief Mikhail Matveevsky told a briefing that the 9M729 missile’s maximum range is 480 km. The Intermediate-Range Nuclear Forces (INF) treaty bans missiles with a range above 500 km.

Standing next to the system, he detailed the missile’s features to assembled foreign media and foreign military officials. Russia has long denied it violates the treaty but Wednesday’s briefing was the first time it has offered details of the missiles in question.

Washington has said it would not be satisfied with Moscow’s offer of a “static display” of the missiles, because they would not show whether they breach the treaty. The U.S. says the missile system should be destroyed in a verifiable manner if Russia wants to keep the INF alive.

Deputy Foreign Minister Sergei Ryabkov, also in attendance, said Moscow decided to unveil the missile after talks with U.S. officials in Geneva this month resulted in “complete failure”.

Last month, Washington gave Russia a 60-day deadline — which ends on February 2 — to dismantle the 9M729 or the U.S. would begin the six-month process of formally withdrawing from the treaty.