Washington, Feb 10 (DPA) The push for another round of international sanctions against Iran over its nuclear activities is moving “fairly quickly” and could be ready in the coming weeks, US President Barack Obama said.

“What we are going to be working on over the next several weeks is developing a significant regime of sanctions that will indicate to them how isolated they are from the international community as a whole,” Obama said at a press conference Tuesday.

Iran announced Tuesday that it had begun the process of enriching uranium to higher concentrations, renewing concerns that it was moving closer to a nuclear weapons capability. Iran maintains the process is solely for civilian energy needs.

“That indicates to us that, despite their posturing that their nuclear power is only for civilian use, that they, in fact, continue to pursue a course that would lead to weaponization,” Obama said.

Iran has so for resisted serious negotiations offered by the US, the European Union, Russia and China to resolve the nuclear dispute. The UN Security Council in recent years has enacted three rounds of limited sanctions to punish Iran for refusing to halt uranium enrichment.

“They have made their choice so far, although the door is still open,” Obama said.

Iran so far has not formally accepted a proposal from the UN nuclear watchdog, the International Atomic Energy Agency, that would have Tehran ship its uranium to a second country for enrichment for medical use.