"We absolutely agree with what he (President Hassan Rouhani) said. This problem must not be solved with ultimatums," Foreign Minister Sergei Lavrov was quoted by Interfax as saying on a visit to Rome on Tuesday.

"Now it is critical to support the constructive approach of the Iranian leadership," he said.

In a press conference on Tuesday, Iran’s new president that Tehran was ready for "serious" talks on its nuclear program without delay and that US calls for tougher sanctions showed a lack of understanding.

Addressing his first news conference since taking office on Saturday, Rouhani said that he would not surrender Iran's rights but that he wanted to allay Western concerns.

"As the president of the Islamic republic, I am announcing that there is the political will to solve this issue and also take into consideration the concerns of the other sides," he said.

"We are the people of interaction and talks, with seriousness and without wasting time, if the other sides are ready."

Rouhani headed Iran's nuclear negotiating team under reformist president Mohammad Khatami in the early 2000s and Western leaders have expressed hope of a more constructive approach in the protracted talks.

Rouhani said there could be no surrender of the right to peaceful use of nuclear energy under the nuclear Non-Proliferation Treaty.

"Iran's peaceful nuclear program is a national issue... we will not give up the rights of the Iranian people," he said.
"We will preserve our rights based on the international regulations."

BA/BA