The conclusion of bilateral agreements on the Caspian Sea does not contradict the provisions of the treaties on trade and navigation which were concluded between the Soviet Union and Iran in 1921 and 1940, said Russian Ambassador to Iran Alexander Maryasov in a RIA Novosti interview. According to him, "in the past few years, at first Russia and Kazakhstan, then Russia and Azerbaijan and also Azerbaijan and Kyrgyzstan achieved accords on dividing the bottom of the northern and central parts of the Caspian Sea by drawing a modified middle line." However, the ambassador said, the modified line, which is determined by two states, in no matter envisages the drawing of any frontier lines or violation of the principle of "common water." "The determination of the legal status of the Caspian Sea is a complicated and long process which calls for an unconditional consensus of the coastal countries," pointed out Alexander Maryasov. But there are other acute and urgent problems, said he, which require prompt solutions. Russia is convinced that "the Caspian coastal countries should achieve consent on preserving and controlling the biological resources and protecting the natural environment of the sea, not waiting for the solution of the problem of the legal regime of the Caspian Sea," said the Russian ambassador to Iran. "The concept of 'a single package,' which presupposes that all the agreements must come into force simultaneously, is not well thought-out, because this concept blocks the possibility of realising the already achieved agreements and makes them hostages of less successful negotiation processes," added Alexander Maryasov.