A regular round of the Russian-US negotiations for preparing the May Russia-US summit on strategic offensive weapons cuts (START) and a declaration of new strategic mutual relations between the two countries will be held on Monday in Moscow. The Russian delegation will be headed by deputy foreign minister Georgy Mamedov, and the US delegation -- by undersecretary of state John Bolton. This is the third visit by John Bolton to Moscow over the past two weeks. Apart from that, the questions of preparing the documents for the May summit were also discussed during the recent visit of Russian foreign minister Igor Ivanov to the USA. Diplomatic sources in Moscow reported that the future START treaty between Russia and the USA will be based on three main principles. First, it will formalise the threshold level of the nuclear warheads to be reduced -- 1,700-2,200 units. Second, the START-1 treaty will remain in force and, third, a working group will be created to discuss all the issues on which the mutually acceptable decisions have not been found yet. The source pointed out that this concerns, above all, the fate of the nuclear warheads to be reduced. The Russian approach, the interlocutor emphasised, is that such warheads should be eliminated. The USA continues to insist that not all nuclear warheads being reduced should be liquidated. Washington believes that a part of them could be stored and used "under certain circumstances".