The French President, Nicolas Sarkozy, has arrived in Moscow for his first bilateral summit with his Russian counterpart, Vladimir Putin.
The two presidents met for the first time at the G8 summit n June
They are expected to discuss energy and industrial co-operation, as well as Iran's nuclear programme and Kosovo.
Mr Sarkozy accused Russia last week of "complicating" the world's problems.
Earlier, he called for the adoption of "increasing sanctions" against Iran, saying previous efforts had pushed Tehran towards greater transparency.
"Between resignation and war - two words which are not in my vocabulary - there is a responsible attitude: increasing sanctions to bring Iran to reason, but also openness to dialogue if Iran chooses to respect its obligations," he told the Russian official newspaper, Rossiyskaya Gazeta, in an interview to be published on Tuesday.
Correspondents say Mr Sarkozy is likely to be backed by the UK and US, but Russia, China and Germany oppose imposing tougher UN sanctions.
"The sanctions have made it possible to obtain first results by pushing Iranian leaders towards greater transparency. So this is proof that they are making the government think," he added, according to a copy obtained by the AFP news agency. "I won't compromise on such a serious issue."
Tehran has denied Western accusations that it is trying to build a nuclear weapon.
'Open and constructive spirit'
Mr Sarkozy is due to hold talks with Mr Putin on Wednesday.
In addition to Iran, the two presidents are likely to discuss the future status of Serbia's breakaway province of Kosovo, whose independence Russia opposes.
They are also due to discuss possible collaboration between the European aerospace firm, EADS, and its Russian counterpart, UAC, on the construction of a new passenger jet, as well as the partnership between the energy giants, Total and Gazprom.
The Russian Deputy Foreign Minister, Alexander Grushko, said the negotiations would take place in an "open and constructive spirit".
"There is no contradiction between the desire of the French to reinforce their friendship with the United States and the development of their traditional partnership with us," he told Interfax news agency.
Mr Sarkozy's office said he would tell President Putin of his "conviction that Russia is and will remain a major player in international relations and an essential partner."
On a visit to Bulgaria last week, Mr Sarkozy said the Russian government was "complicating" world affairs and that it "should understand that big countries have not only rights, but also responsibilities".