Britain confident of climate deal in Mexico: report
"I am confident we can get an agreement as we have made a lot of progress over the last year," Miliband said, responding to a question from Reuters whether a deal can be reached in Mexico in November this year.
"We are trying to get consensus from 192 countries from very different places to be part of an agreement. That is tough and that's what Copenhagen showed," he added.
A U.N. climate summit in Copenhagen in December merely noted a non-binding accord on broad principles, without commitments to binding greenhouse gas emissions cuts.
Talks ended with a bare-minimum agreement that fell far short of its original goal of forging a replacement for the climate-protecting Kyoto Protocol when it expires in 2012.
"It was definitely a disappointment. We wanted a tract to a legal treaty," Miliband said, referring to the summit.
"But the year itself was a success. I genuinely believe the world moved in the course of the year in a way it wouldn't have done without the coalition that was assembled."
Miliband said the course to a legally binding agreement will be tough, with "bumps" along the way. A January 31 deadline for countries to commit to emissions cuts is fast approaching.
"We have to broaden, strengthen and deepen the agreement. Broaden it because we only have representatives from around 50 countries signing up. It is very important that we broaden the number of countries involved," Miliband said.
"We need not only commitments on the January 31 but we need those commitments ratcheted up during the course of the year."
European Union environment ministers will seek a strategy for reviving global climate talks at a meeting in Spain this week.
Miliband said developing countries have a lot to gain from signing up to a legally binding pact.
"For some developing countries, a legal treaty felt like a bridge too far. Personally, I feel we can convince them they have less to fear but more to gain from the assurance of a legal agreement."
(Reporting by Nina Chestney; Editing by Marguerita Choy)