UNITED NATIONS - With the United States stepping up the pressure, diplomats from six major powers discussed possible new sanctions against Iran over its nuclear programme at a meeting on Saturday but failed to reach an agreement. China told the meeting that the calls for new sanctions against Iran are premature. Robert Cooper, the European Unions political director who chaired the meeting, said the US, Russia, China, Britain, France and Germany concluded that Iran has failed to follow up on an agreement in principle in October that the Islamic republic exchange uranium for nuclear fuel, in particular by refusing further meetings to discuss the nuclear issue. He said the six nations remain committed to a dual track approach to Iran to try to defuse global fears over its nuclear programme-diplomatic and political engagement on the one hand and possible new sanctions if Tehran refuses to rein in its nuclear ambitions. That implies that we will continue to seek a negotiated solution, but consideration of appropriate further measures has also begun, Cooper told reporters after the 2 1/2-hour closed-door meeting. Russias Deputy Foreign Minister Sergei Ryabkov said the six powers reconfirmed our desire to meet again with the Iranians to discuss their October proposal. We have talked mostly today on the second track, but it doesnt mean that we should abandon the first one, he said. We do believe there is still time for meaningful political engagement, and efforts to find a solution. Thats something that Russia has always advocated. While the other countries sent senior diplomats, China sent a counsellor from its UN mission to the meeting, a suggestion the country did not see the meeting as important. Yafei, the former vice minister of foreign affairs, has now been appointed the Chinese ambassador to the UN in Geneva and it is unclear who will eventually replace him in the talks. Both China and Russia voted in the Security Council for three previous rounds of sanctions, but only China has been outspoken in its recent opposition. Russia is said to be upset that its offer to further enrich Iranian uranium at its facilities was rebuffed and that the Iranians did not seem serious about entering negotiations. The Obama administration has also been dismayed that Iran has been dismissive of a yearlong effort to engage it, diplomats said. Iran maintains that its desire to enrich uranium is only for peaceful civilian purposes, but Western powers accuse it of using that as a smokescreen to develop nuclear weapons. US Secretary of State Hillary Clinton said on Monday that the Obama administration has concluded that the best way to pressure Iran to come clean on its nuclear ambitions is to impose new sanctions aimed at the countrys ruling elite.