'GREEN LIGHT' FOR US CLIMATE DEAL SUPPORT.
It follows the US president's announcement he plans to cut Americans' dependence on foreign oil.
After resisting international action to cut greenhouse gases, he wants US drivers to cut petrol use by a fifth in 10 years.
In his annual State of the Union address, Bush said: "For too long our nation has been dependent on foreign oil. This dependence leaves us more vulnerable to hostile regimes and to terrorists."
Blair said the speech made him "optimistic" for an international agreement including the US. He suggested it could be signed at the G8 meeting this summer, his last major conference as PM.
Blair added: "I think there is a different attitude around the world on this issue."