From the Document: "On February 2, 2019, the United States suspended its participation in the Intermediate-Range Nuclear Forces (INF) Treaty and notified Russia of its intent to withdraw from the treaty. Under Article XV of the treaty, the withdrawal will take effect in six months. [...] President Trump first indicated that the United States would withdraw from INF on October 20, 2018. He not only cited Russia's violation, but also argued that the United States is at a disadvantage with respect to China because the latter is not bound by the treaty's limits. On December 4, 2018, after a meeting of NATO's [North Atlantic Treaty Organization] foreign ministers, Secretary of State Pompeo declared that Russia was in material breach of the treaty and announced that the United States would suspend its obligations, effective in 60 days, 'unless Russia returns to full and verifiable compliance.' This 60-day period ended on February 2, 2019."
CRS In Focus, IF11051
Congressional Research Service: https://crsreports.congress.gov/