Iranian President Mahmoud Ahmadinejad has congratulated Vladimir Putin on his landslide victory in Russia's presidential elections.
In a letter to the president-elect, Ahmadinejad said Putin's new term as president would end "discrimination and unilateral approaches" to world problems.
Putin received more than 63% of the vote in the poll, which has been hit by claims of widespread voter fraud.
Police in Moscow and St Petersburg made hundreds of arrests after protests were held against the results on Monday.
Opposition leader Alexei Navalny vowed to continue his challenge to Putin despite the arrest.
Navalny has been called "the man Vladimir Putin fears most" for his role as the de facto leader of the movement against the Russian president.
"We will certainly stage mass protests, and thousands, tens of thousands people will come to the streets of Moscow and other cities and will refuse to leave. We will definitely do this, and we will be doing that until we win and achieve what we want," he said.
The Russian president has been a strong supporter of the country's regional partners Iran and Syria, and last week admonished the United States and the Arab League for issuing threats of military strikes against Iran's nuclear facilities.
"I very much hope the United States and other countries ... do not try to set a military scenario in motion in Syria without sanction from the UN Security Council," Putin said.
On Iran Ahmadinejad said "the consequences will be truly catastrophic" if any attacks were launched.
Ahmadinejad did not fare as well in his own electoral battle recently, after losing ground in his battle with Supreme Leader Ayatollah Khamenei for parliamentary seats.
Although both leaders are equally conservative, Ahmadinejad has been reportedly struggling with the supreme leader's faction for greater control over security and international affairs.
The opposition movement in Iran was barred from standing in the polls, and the supreme leader's supporters sanctioned each candidate who stood.
Final tallies have not been released but indications are that Ahmadinejad's faction did relatively poorly in the poll.
Even his sister, Parvin Ahmadinehad, who stood as a candidate in the family's home region, lost her race.