The US will withdraw from a landmark nuclear missile pact with Russia, Donald Trump announced on Friday – ending an agreement that has been a cornerstone of superpower arms control since the Cold War.

The Trump administration’s move, which has been expected for months, follows years of unresolved dispute over Russian compliance with the Intermediate-Range Nuclear Forces, or INF, treaty.

The announcement begins a six-month countdown that could lead to a permanent US withdrawal from the accord.

During that time, Washington could choose not to pull out of it, if Russia comes into compliance with the treaty. However, experts say that is not likely.

Tim Wright, treaty coordinator for the International…