The meeting of major economies convened in Paris last week ended in deadlock with delegates again split on whether to set a target to halve greenhouse gas emissions by 2050.

The meeting of the world's 17 largest polluters – which formed part of a series of conferences instigated last year by the US to run parallel to UN climate change talks – ended with delegates agreeing on the urgent need for action on climate change, but split on the best policy mechanisms to adopt to curb emissions.

Daniel Price, US deputy national security advisor for international economic affairs, told reporters at the conference that "significant progress" had been made at the talks with delegates largely agreed on the need to share clean technologies and increasingly willing to consider sectoral emission reduction goals for carbon intensive industries such as steel and cement.

However, negotiators were again at loggerheads over proposals for a binding target to cut emissions by 50 per cent by 2050.

The EU, Japan and Canada have all been lobbying hard for such a target to be set, but representatives of developing economies at the talks said they would not sign up to such a goal until they see more action from the US to cut emissions. The US, for its part, has said it is still giving serious consideration to the proposed target, but has repeatedly resisted calls from the international community to set emissions goals.

In an attempt to break the deadlock, delegates agreed to two further meetings ahead of the next scheduled meeting in July, which is to be held alongside the G8 summit in Japan.

The Paris talks closed as the leaders of 18 US states signed an agreement at a meeting at Yale University to step up pressure on the presidential candidates to ensure they are all ready to deliver a significant toughening of US climate policy as soon as the eventual winner of this November's election takes up residence in the White House.

According to the agreement, California, Illinois, Florida, New York and 14 other states will "reach out to major presidential candidates as a means of shaping the first 100 days of the next administration", on climate policy.

Speaking at the conference, California governor Arnold Schwarzenegger said that "President McCain, President Obama, President Clinton would all shift this country to a much higher level on climate change," adding that rapid changes in the US position on climate change could be delivered as soon as the first half of next year.