LOS ANGELES ~ US president-elect Barack Obama vowed this week he would “engage vigorously” in global climate change talks and that denial was no longer an acceptable response to global warming.

Obama said in a surprise video message to a summit of US state governors on climate change here on Tuesday that he would show new leadership on the issue as soon as he takes office in January.

The president-elect also addressed his message directly to delegates at United Nations climate change talks in Poland next month.

“While I won’t be president at the time of your meeting, and while the United States has only one president at a time, I’ve asked members of Congress who are attending the conference as observers to report back to me on what they learn there.

“And once I take office, you can be sure that the United States will once again engage vigorously in these negotiations, and help lead the world toward a new era of global cooperation on climate change.

“Now is the time to confront this challenge once and for all. Delay is no longer an option. Denial is no longer an acceptable response. The stakes are too high. The consequences, too serious.”