The Kremlin press service said Monday Putin would visit Iran despite the threat, but made no comment on the alleged plot.
Putin's trip to Iran will test Russia's ability to wield international political influence amid the ongoing controversy surrounding Iran's nuclear program.
He will attend a Caspian summit, the second ever, which will be a good opportunity for the parties to exchange opinions on cooperation in different areas with regard to the Caspian Sea, including measures to maintain peace, security and stability in the region.
Russia, Azerbaijan and Kazakhstan signed an agreement in 2003 dividing the northern part or 64% of the sea among themselves, but Iran and Turkmenistan rejected the proposal.
The 2002 summit in Ashgabat, Turkmenistan addressed the legal rights of Caspian states to explore the huge oil reserves beneath the world's largest saline lake.