Former President Barack Obama challenged President Donald Trump’s decision to withdraw from the Paris Climate agreement, describing it as the “absence of American leadership.”

“In Paris, we came together around the most ambitious agreement in history about climate change, an agreement that even with the temporary absence of American leadership, can still give our children a fighting chance,” Obama said during a speech in Indonesia on Saturday.

Obama stressed that even though Trump made the decision to pull the United States out of the Paris agreement, “technically it’s not out yet.”

The president spoke in lofty terms about the state of the world warning that it was a “crossroads” as many countries were slipping into nationalism.

“We start seeing a rise in sectarian politics, we start seeing a rise in an aggressive kind of nationalism,” he said. “We start seeing both in developed and developing countries an increased resentment about minority groups and the bad treatment of people who don’t look like us or practice the same faith as us.”

Obama spoke generally about world leaders who refused to embrace tolerance and diversity.

“I don’t believe the future favors strongmen. I believe the future favors those who promote tolerance … who are open to differences and learn from everyone,” he said.

Obama spent 10 days vacationing in his childhood home of Indonesia, visiting cultural and historical sites.

“Indonesia is made of thousands of islands, hundreds of languages, scores of regions and ethnic groups. So my time here made me cherish and respect for people’s differences,” he said.