Jansa, making a pitch for multilateralism, said no one country could solve the world's problems.
"The world is now complex," Jansa said. "Nobody, alone, can solve all problems. World peace, security, and promotion of democracy, climate change, and the fight against poverty are global challenges today."
Bush concurred and he paid tribute to Jansa and Slovenia's journey over the past 20 years. He said that despite some disagreements Europe and the United States share strong ties based on fundamental, common values.
"The thing that unites us, and this is important for all of us to realize, is that we share common values and people say, 'Oh, that's just corny, that doesn't mean anything.' It means a lot if you believe in human rights and human dignity and rule of law and freedom to speak and freedom to worship. That's a lot," Bush said. "That's a foundation for a very firm and lasting relationship."
The two sides issued a joint statement on Iran. The United States and the EU warned they could deploy extra measures against Iran on top of existing UN sanctions if Tehran does not suspend its uranium enrichment.
Those measures were not detailed. But the U.S. president, once again, explained why both Europe and the United States want to see Tehran abandon its enrichment program.
"We've always made it clear to the Iranians that there is a better way forward, that if they want to have a relationship with the EU-3, the United States, and other countries, all they have to do is verifiably suspend their enrichment program," Bush said. "The reason why that is important is if they learn to enrich, it means they've learned a key part of developing a nuclear weapon. And if they end up with a nuclear weapon, the free world is going to say, 'Why didn't we do something about it at the time, before they developed it.' And so now is the time for there to be strong diplomacy."
Tehran insists the program is strictly for civilian purposes -- generating electricity -- and has so far resisted such appeals.
But Bush recalled recent statements by the Iranian leadership calling for Israel's destruction, saying it highlighted the potential threat posed by Tehran -- especially if it acquires nuclear weapons.
"If you were living in Israel, you'd be a little nervous, too, if a leader in your neighborhood announced that he'd like to destroy you," he said. "One sure way of achieving that means [of destruction] is through the development of a nuclear weapon. Therefore, now is the time for all of us to work together to stop them."
On other issues, the EU and the United States spoke with one voice today. Bush predicted a new international deal to combat climate change could be passed this year.
Barroso said the two sides were also working together to overcome the current global economic turbulence.
Bush now travels to Germany, for dinner and talks with German Chancellor Angela Merkel.