WASHINGTON: At the international conference on climate change in Copenhagen in December 2009, US President Barack Obama forced himself into a room where the then Chinese premier Wen Jiabao was holding a secret meeting with the then Indian Prime Minister Manmohan Singh and other leaders.Giving a blow by blow account of the incident, of which she was part as the then secretary of state, Hillary Clinton in her memoirs ' Hard Choices ' writes that the purpose of China was to isolate the United States by bringing together countries like India, Brazil and South Africa on its side.But Obama's determination and presence of mind thwarted such a move, she writes."President Obama and I were looking for Premier Wen Jiabao in the middle of a large international conference on climate change in Copenhagen, Denmark," she recalls."We knew that the only way to achieve a meaningful agreement on climate change was for leaders of the nation's emitting the most greenhouse gases to sit down together and hammer out a compromise — especially the US and China," she said. "But the Chinese were avoiding us.""Worse, we learned that Wen had called a 'secret' meeting with the Indians, Brazilians, and South Africans to stop, or at least dilute, the kind of agreement the United States was seeking. When we couldn't find any of the leaders of those countries, we knew something was amiss and sent out members of our team to canvass the conference centre," she writes."Eventually they discovered the meeting's location.After exchanging looks of 'Are you thinking what I'm thinking?' the president and I set off through the long hallways of the sprawling Nordic convention center, with a train of experts and advisers scrambling to keep up," she writes in her book."Later we'd joke about this impromptu 'footcade', a motorcade without the motors, but at the time I was focused on the diplomatic challenge waiting at the end of our march. So off we went, charging up a flight of stairs and encountering surprised Chinese officials, who tried to divert us by sending us in the opposite direction. We were undeterred," she says.When they arrived outside the meeting room, there was a jumble of arguing aides and nervous security agents, she says.Robert Gibbs, the White House press secretary, got tangled up with a Chinese guard, she adds.In the commotion the president slipped through the door and yelled, 'Mr Premier!' really loudly, which got everyone's attention."The Chinese guards put their arms up against the door again, but I ducked under and made it through," Clinton writes recounting the incident."In a makeshift conference room whose glass walls had been covered by drapes for privacy against prying eyes, we found Wen wedged around a long table with Indian Prime Minister Manmohan Singh, Brazilian President Luiz Inacio Lula da Silva, and South African President Jacob Zuma.Jaws dropped when they saw us. 'Are you ready?' said President Obama, flashing a big grin," Clinton claims."Now the real negotiations could begin. It was a moment that was at least a year in the making," she adds.