Collectively, the summit participants said all signatories to the nuclear Non-Proliferation Treaty have a right to develop peaceful nuclear technology.
 
Iran is embroiled in a nuclear standoff with Western nations which accuse Tehran of seeking atomic weapons, a charge Tehran denies.
 
Washington has refused to rule out the use of military action if diplomacy fails to resolve the row.
 
Azerbaijan facilities
 
Russian media have speculated that Washington might be trying to negotiate with Azerbaijan on the right to use military facilities in the Caucasus republic. Azeri officials deny this.
 
Putin is the first Kremlin leader to travel to Iran since Josef Stalin, the former Soviet leader, attended a wartime summit with Winston Churchill, former British prime minister, and Franklin Roosevelt, former US president, in 1943.
 
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Al Jazeera's report on the Caspian Sea summit

It's not just bilateral issues that are dominating the headlines.
 
Western powers are watching the Putin visit very closely for any signs there's a shift in Moscow's policies over Iran nuclear programme, a matter Iran says is closed.
 
While the US, UK and France have sought tougher sanctions against Iran, Russia has traditionally shied away from criticising its nuclear energy programme.
 
Putin has favoured diplomacy over sanctions, but if the bilateral relations between the two countries cool down, the Western powers may be empowered to seek the a third round of sanctions with Russian support.
 
Co-operation plea
 
Mahmoud Ahmadinejad, the Iranian president, welcomed Putin and the other leaders on Tuesday with a call for closer co-operation on security issues and deeper economic ties.
 

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He said: "This co-operation - which is intended to prevent military competition in the sea and also warding off hostile forces and at the same time fighting organised crime - will require the establishment of a regional body in the near future."
 
Earilier on Tuesday, Manouchehr Mottaki, the Iranian foreign minister, welcomed Putin at the airport.

Alireza Ronaghi, Al Jazeera's correspondent in Tehran, said the government in Tehran is likely to pressure Russia to complete work on the nuclear facility in the southern port city of Bushehr.
 
Work has stopped at the plant because of financing problems according to the Russian contractors.

Assassination plot
 
Putin's trip had been overshadowed by rumours that he might be the target of an assassination attempt.
 
The Russian Interfax news agency reported on Sunday that Putin had been advised of an assassination plot against him that was to take place during his visit to Tehran.
 
But Putin refused to cancel his visit, saying the security services "must do their work".

 

"If you react to various threats and recommendations of the security services, then you should sit at home".

 
Earlier Tehran described reports of a plot against Putin as "totally baseless".

Putin, right, is the first Russian leader to visit Iran since 1943 [AFP]