Russia’s Defence Minister Sergei Shoigu on Tuesday said the country must develop new types of missile systems in the next two years after Washington and Moscow ripped up a key arms control treaty. The United States has repeatedly accused Russia of violating the Intermediate-Range Nuclear Forces (INF) agreement and on Friday President Donald Trump said Washington was starting a process to withdraw from the treaty in six months. In a tit-for-tat move on Saturday, Russian President Vladimir Putin said Moscow was also leaving the treaty and beginning work on new types of weapons that would breach the crucial Cold War-era agreement. At a meeting with officials on Tuesday, Mr. Shoigu said Russia should develop two new missile systems in the next two years. “During 2019-2020 we have to develop a land-based version of the seaborne Kalibr system equipped with a long-range cruise missile which showed good results in Syria,” he told Defence officials. “Over the same period we will also have to create a land-based missile system with a long-range hypersonic missile,” he said. The Defence Minister said the plans had been approved by Mr. Putin. The INF agreement forbids ground-launched, short- and intermediate-range missiles, but not those launched from the air or sea — which Russia already has.