US President Barack Obama touted a track record of foreign policy success Monday and implicitly criticized the positions of his Republican rival Mitt Romney, who heads this week to Europe and the Middle East.

Obama reminded an audience of military veterans in Nevada of his vow four years ago to "take the fight to our enemies and renew our leadership in the world."

"As president, that's what I've done," Obama told the annual meeting of the Veterans of Foreign Wars (VFW), citing his ending of the Iraq war, the drawdown from Afghanistan, and restoration of alliances that had frayed over the fight against Al-Qaeda and a devastating global recession.

"As you reflect on recent years, as we look ahead to the challenges we face as a nation and the leadership that's required, you don't just have my words, you have my deeds," Obama added.

"You have my track record. You have the promises I've made, and the promises that I've kept."

Obama eventually brought 150,000 US troops home from Iraq by last December, and without mentioning Romney by name called out the opponents of that plan.

"Some said that bringing our troops home last year was a mistake. They would have kept tens of thousands of our forces in Iraq indefinitely without a clear mission," Obama said.

And while he mentioned his pledged to "finish the job in Afghanistan," he added there were critics "who argued against a timeline for ending this war or against talking about it publicly."

"When you're commander in chief, you owe the troops a plan," said Obama, who has announced a 2014 end of combat operations in Afghanistan.

"You owe the country a plan. And that includes recognizing not just when to begin wars, but also how to end them."

Romney, who addresses VFW on Tuesday, has accused Obama of "appeasing" US enemies and faulted the president for setting an Afghanistan withdrawal date.

But Obama argued how he has consistently taken the fight to American enemies, and how as a candidate in 2008, he said he would go after Al-Qaeda chief Osama bin Laden even if it meant going into Pakistan.

That comment drew criticism from Romney and other Republicans -- something the White House was eager to mention last May on the one-year anniversary of bin Laden's death in a secret US raid in Pakistan.

Obama and Romney have been locked in a brutal White House campaign ahead of the November election, and while most of the focus has been on domestic issues like the struggling US economy, the debate shifted to foreign policy Monday.

"Because we're leading around the world, people have a new attitude toward America," Obama said. "There's more confidence in our leadership. We see it everywhere we go."

Romney, who launches a six-day tour Thursday to Britain, Israel and Poland in a bid to spruce up his foreign policy image, will make the case later this week that America can do better, particularly in the Middle East, where the Republican said Obama's policy is misguided and weak.

In an interview due to air later Monday on CNBC, Romney struck out against Obama's policy on Syria, saying "from the very beginning we misread the setting in Syria" and should have been "very aggressive" from the early days of the uprising that President Bashar al-Assad must step down.

"The Middle East... is a place of tumult and disarray and the world looks for American leadership and American strength," Romney said.