By Simon Robinson

ST PETERSBURG, Russia (Reuters) -President Vladimir Putin on Thursday refused to discuss the possibility that Israel and the United States would kill Iranian Supreme Leader Ayatollah Ali Khamenei and said the Iranian people were consolidating around the leadership in Tehran.

Israeli Prime Minister Benjamin Netanyahu has openly speculated that Israel's military attacks could result in regime change in Iran while U.S. President Donald Trump said on Tuesday that the U.S. knew where Khamenei was "hiding" but that Washington was not going to kill him "for now".

Asked what his reaction would be if Israel did kill Khamenei with the assistance of the United States, Putin said: "I do not even want to discuss this possibility. I do not want to."

When pressed, Putin said he had heard the remarks about possibly killing Khamenei but that he did not want to discuss it.

"We see that today in Iran, with all the complexity of the internal political processes taking place there...that there is a consolidation of society around the country's political leadership," Putin told senior news agency editors in the northern Russian city of St Petersburg.

Putin said all sides should look for ways to end hostilities in a way that ensured both Iran's right to peaceful nuclear power and Israel's right to the unconditional security of the Jewish state.

Putin was speaking as Trump kept the world guessing whether the U.S. would join Israel's bombardment of Iranian nuclear and missile sites and as residents of Iran's capital streamed out of the city on the sixth day of the air assault.

Putin said he had been in touch with Trump and with Netanyahu, and that he had conveyed Moscow's ideas on resolving the conflict while ensuring Iran's continued access to civil nuclear energy.

IRANIAN NUCLEAR FACILITIES

Questioned about possible regime change in Iran, Putin said that before getting into something, one should always look at whether or not the main aim is being achieved before starting something.

He said Iran's underground uranium enrichment facilities were still intact.

"These underground factories, they exist, nothing has happened to them," Putin said.

"It seems to me that it would be right for everyone to look for ways to end hostilities and find ways for all parties to this conflict to come to an agreement with each other," Putin said. "In my opinion, in general, such a solution can be found."

Asked if Russia was ready to provide Iran with modern weapons to defend itself against Israeli strikes, Putin said a strategic partnership treaty signed with Tehran in January did not envisage military cooperation and that Iran had not made anyh formal request for assistance.

Russian Deputy Foreign Minister Sergei Ryabkov said on Wednesday that Moscow was telling the United States not to strike Iran because it would radically destabilise the Middle East.

A spokeswoman for the Russian Foreign Ministry also warned that Israeli strikes on Iranian nuclear facilities risked triggering a nuclear catastrophe.

Putin said that Israel had given Moscow assurances that Russian specialists helping to build two more reactors at the Bushehr nuclear power plant in Iran would not be hurt in air strikes.

Putin said that Moscow had "a very good relationship with Iran" and that Russia could ensure Iran's interests in nuclear energy.

Russia has offered to take enriched uranium from Iran and to supply nuclear fuel to the country's civil energy programme.

"It is possible to ensure Iran's interests in the field of peaceful nuclear energy. And at the same time, to address Israel's concerns about its security," Putin said. "We have outlined them (our ideas) to our partners from the USA, Israel and Iran."

(Additional reporting by Vladimir Soldatkin and Gleb Bryanski in St Petersburg, Russia, Anastasia Lyrchikova and Dmitry Antonov in Moscow and Darya Korsunskaya in London; editing by Guy Faulconbridge/Andrew Osborn)