TEHRAN, Iran (AP) – Russian President Vladimir Putin pledged Monday to negotiate with Iran on behalf of the international community in their nuclear standoff, although he didn’t come to Tehran as scheduled amid warnings of a possible assassination plot.

Putin’s planned trip, the first here by a Kremlin leader since World War II, raised hopes that personal diplomacy could find a solution to the impasse over the Iranian nuclear program, but he delayed his arrival, which had been set for Monday evening.

The Russian leader insisted to reporters in Germany that he was going ahead with the trip, but the Kremlin declined to discuss details.

The official Iranian news agency said late Monday that Putin had only put off his trip by several hours and would be in Tehran early today in time for a Caspian region summit.

“Putin will arrive in Tehran at the head of a delegation tomorrow morning,” the Islamic Republic News Agency said, quoting Iran’s presidential press service.

Iran gave no further details, and Kremlin officials wouldn’t comment on reasons for the delay or say exactly when Putin would arrive.

Officials in Germany, where Putin wrapped up a two-day visit, said they could not say where the Russian leader was.

Iranian Foreign Ministry spokesman Mohammad Ali Hosseini dismissed reports about the purported assassination plot as disinformation spread by adversaries hoping to spoil good relations between Russia and Iran.

Putin’s visit to Tehran, the first such trip by a Kremlin leader since Josef Stalin attended a 1943 wartime summit with Winston Churchill and Franklin D. Roosevelt, is being closely watched for any possible shifts in Russia’s carefully hedged stance in the nuclear standoff.