Reuters Zurich, May 26 -The head of the UN nuclear supervision agency said in an interview with the Financial Times published on Wednesday that the Iranian uranium concentration plan is very worrying.

Rafael Grossi, director of the International Atomic Energy Agency (IAEA), said that Iran is condensed uranium in a purity level that can only be achieved with bombs.

It is a very serious thing to condense uranium to 60%of a country-only the country that manufacture bombs can reach this level, and Gross told the newspaper.60%are almost weapon levels, and the commercial concentration level is 2%and 3%.

He said that the development of its plan was Iran's sovereign right, but he added: This is a degree of vigilance.

Gross said that most of the measures taken by Iran can be relatively easy to reverse, but he added that the level of research and development that has occurred is a problem.

It is difficult to catch the mountains when the tiger returns to the mountain-once you know how to do it, you just know.The only way to suppress was to verify, he said.

Iran's plan has grown and has become more complicated, so it is impossible to return to 2015.What you can do is to make their activities below the 2015 parameters.(End)