LISBON, July 6 (Xinhua) -- Former U.S. President Barack Obama said it is still possible to bring countries together to address climate change under the Paris Accord and solve a problem that transcends borders.

"What we see is that with the Paris Accord ... we can still have countries on a common agenda," said Obama, who gave a keynote speech at the Climate Change Leadership Summit in Porto, northern Portugal, on Friday.

Asked about the future of the Paris Accord, he said his successor had a different position on climate change, adding that the United States will once again align with science in the future.

"The bad news is that my successor did not agree with me. The good news is that other efforts were emerging in the economy and companies were realizing the advantages of investing in clean energy," he said.

Obama said that he is sure that the United States will return to the Paris Accord and that "more and more countries will take bold goals in the future" in combat climate change.

"To continue this program, we would have to join hands with other countries," he added.

Joao Pedro Matos Fernandes, Environment Minister of Portugal, said at the summit that his country is preparing to launch a plan to tackle climate change.

"Our territory needs to be more resilient to these changes. That is why adaptation to climate change is one of the main challenges for Portugal," he said.

The minister added that Portugal is "committed" to becoming a carbon-neutral country by 2050 and is creating a national road map for this purpose, involving civil society, business and universities.