Presidential candidate Barack Obama, who just completed a weeklong tour abroad, described his foreign policy approach as one that balances the promotion of human rights with the need to put the highest priority on the issues most crucial to America's security.

In an interview with Reuters on his flight back on Saturday from the Middle East and Europe, the presumptive Democratic nominee said his approach was "pragmatist."

He also took a tough line on Iran and gave a guardedly favourable impression of Iraqi Prime Minister Nuri al-Maliki and Afghan President Hamid Karzai after visits to their countries.

Here are some excerpts from the interview:

REALISM VS. IDEALISM

Obama labels his foreign policy approach "pragmatist." Asked what he means by that, he replied, "There's always been a tension in American foreign policy between realism and idealism.

"When we're at our most effective, we are both concerned with protecting our values and ideals in the world but also mindful of how difficult it is to move societies in particular directions," Obama said. "So we've got to have some humility about what we can accomplish at a given time."

ON RUSSIA AND CHINA

Obama said the U.S. relationships with Russia and China were "great examples" of balancing the promotion of values with putting the top focus on America's security interests.

He said the United States must speak out on human rights issues such as genocide in Sudan while putting as a "very, very high priority" enlisting help to pressure Iran on its nuclear program.

"That is a very, very high priority for our own safety and security, for the safety and security of the region, for the safety of our ally Israel. It's going to be very hard to pressure them effectively if we don't have China and Russia on board," he said. "So we may not be able to do everything all at the same time. We've got to pick and choose our priorities on foreign policy, just as we do on domestic policy.

PRESIDENT GEORGE H.W. BUSH'S FOREIGN POLICY

Obama expressed admiration for the deftness of President George H.W. Bush - the current president's father - in knowing not to "overreach" on foreign policy.

"I think they managed the end of the Cold War with extraordinary sophistication that could have gone wrong in all sorts of ways. They didn't overreach," he said. Concerning the first Gulf War, "they were very hard-headed but also worked very diligently in terms of rounding up our allies."

IRAN

Obama said in Paris last week that Iran must not wait for the next U.S. president to make a deal on its nuclear program. Elaborating on that, he told Reuters the comment was meant to be supportive of the Bush administration's move toward greater engagement with Iran when it sent William Burns, a senior U.S. diplomat, to talks with Iranian officials.

"I want the Bush administration to be successful in working with the Europeans to get Iran to stand down on its nuclear weapons program. I don't think (an Iranian nuclear weapon) is an acceptable outcome," Obama said. "Bill Burns is a very serious guy. And the Iranians should take that gesture seriously."

GOALS IN AFGHANISTAN

Obama describes Afghanistan as the war the United States must win. Asked how he defines "winning," he replied, "I think our goals have to be very modest but they will still be very difficult to meet. We should want a functioning Afghan government that can maintain its own security and territorial integrity."

Obama said the United States should help in moving the development process along "but our highest priority is making sure that the Taliban and al Qaeda can't continue to use that region from which to launch attacks around the world.

"If we have routed them and scattered them, that would be success," he said.

ON HIS MEETINGS WITH MALIKI AND KARZAI

"I think that both of them are obviously working under the most difficult possible circumstances. And I think that they have worked well with the coalition forces in their respective countries," Obama said.

On Maliki, Obama said: "I think he recognizes that the Iraqi government both has to become more efficient and more inclusive. Whether he understands the degree to which that has to happen . I can't tell."

Obama said Karzai was a "smart and charming person."

"I think that the vision he has for Afghanistan long term has a lot of good elements but I think it was very important for the Afghan people to feel as if this federal government is delivering for them and right now they are not seeing that," Obama said.

He said urged Karzai to do more to fight corruption and counter the narcotics trade.