- NATO has said Russia's SSC-8 missile violates terms of a 1987 missile treaty.
- The U.S. says it will exit the treaty unless Russia stops their production.
- But Russia has continued to develop and site the missiles within range of Europe.
NATO said Russia must destroy its short-range nuclear-ready cruise missile system, or the alliance will be forced to respond.
The U.S. has previously said it will quit a decades-old missile treaty with Russia if the latter fails to destroy the missile, labeled the SSC-8 by NATO.
The 1987 INF Treaty between the U.S. and Russia sought to eliminate nuclear and conventional missiles, as well as their launchers, with short ranges (310–620 miles) and intermediate ranges (620–3,420 miles).
NATO has said the SSC-8 violates those terms and that Russia has been deploying the system at locations which could threaten countries across Europe.
Speaking at a press conference in Brussels Tuesday, NATO Secretary-General Jens Stoltenberg said Russia had just five weeks to scrap the system and save the treaty.
"We call on Russia to take the responsible path. Unfortunately, we have seen no indication that Russia intends to do so," he said.
Stoltenberg will chair a meeting of NATO member defense ministers which is due to begin Wednesday. He said that gathering, which will include U.S. acting Defense Secretary Mark Esper, would look at NATO's next steps "in the event that Russia does not comply."
The NATO chief said the response would be "defensive, measured and co-ordinated," but would not result in the deployment of land-based nuclear missiles.
"As Russia is deploying new missiles we must ensure our deterrent is effective. This is NATO's job."
At the same press conference, Stoltenberg outlined the breakdown of individual country contributions to defense among member nations.
The NATO guideline sits at 2% of gross domestic product but only around seven of the 29 countries are expected to satisfy that target by 2019.
Those countries are Latvia, Poland, Romania, the U.K., Estonia, Greece and the United States. The U.S. is by far the biggest spender on defense, routing around 3.5 percent of its GDP total toward the sector.
NATO said that its estimate for 2019 would see the levels of NATO member cash spent on defense rise by about 3.9 % from 2018 levels.