Moscow, June 11 : Just days ahead of the much-anticipated meeting between Russian President Vladmir Putin and his US counterpart Joe Biden, Prime Minister Mikhail Mishustin has signed an order to nullify the Moscow-Washington Memorandum of Understanding (MoU) on "open ground" that facilitated travels for diplomats in their host country. Mishustin on Thursday asked the Russian Foreign Ministry to inform the US side of the termination, reports Xinhua news agency. The MoU signed in Washington in June 1992 allowed Russian and US diplomats to tour their host country simply on notification, without seeking permission. The intention to terminate the agreement was first announced by the Russian Foreign Ministry on April 16, when it unveiled a slew of countermeasures to "hostile US actions". Foreign Minister Sergey Lavrov had said that in accordance with the document, certain categories of diplomats, from counsellors and all the way down, are supposed to notify the authorities of the host country each time they plan a trip beyond the 25-mile zone around the general consulate's host city. According to Lavrov, the Americans "completely ignored" this requirement". The Putin-Biden summit on June 16 in Geneva comes at a time of great tension between Washington and Moscow. Relations between Washington and Moscow have been adversarial in recent years. The two sides have obvious differences on issues related to Ukraine, cybersecurity, human rights, and US election interference. /IANS