Zardari, elected by legislators Saturday, was long on platitudes but short on specifics while meeting with media after taking the oath of office in a short ceremony at the presidential palace. He was chosen to replace Pervez Musharraf, a U.S. ally who resigned under pressure last month.
With President Hamid Karzai of neighboring Afghanistan by his side for a news conference, the widower of former two-time Prime Minister Benazir Bhutto said he hoped to turn Pakistan's negatives into positives.
"As far as America is concerned, the fact that we are on the globe and we are in the eye of the storm, I consider that an opportunity," Zardari said, noting that most countries welcome foreign investment.
"I intend to take that and make it our strength. We intend to take the world with us in developing the future of Pakistan and changing the future of our neighbors," he said.
Karzai said he found common ground with Zardari.
"For each step that you take in the war against terrorism for bringing peace to two countries, for bringing stability to two countries, Afghanistan will take many, many steps with you," he said.
Private talks between Zardari and Karzai were likely a bit more contentious. Afghanistan has accused Pakistan of failing to take action against Taliban militants based around the countries' common border.
Asked about allegations that Pakistan's intelligence agency had collaborated with militants waging war on Afghanistan's U.S.-backed government, Zardari said the neighbors would work together on any "weaknesses."
The United States came to depend heavily on Musharraf for cooperation to capture or kill al Qaeda leaders who plotted the 9/11 attacks on America and fled Afghanistan after the U.S.-led invasion in 2001 toppled the Taliban regime.
However, the Taliban revived on Musharraf's watch, and al Qaeda chiefs Osama bin Laden and Ayman al-Zawahri remain on the run, probably somewhere in Pakistan's tribal areas.
Washington has increasingly taken matters into its own hands in recent weeks, with controversy erupting every time civilians become casualties. Missile strikes in Pakistan's northwest have killed dozens, and U.S.-led forces last week took part in a helicopter-backed ground assault that killed at least 15.
"Regrettably, there will be times when our pursuit of the enemy will result in accidental civilian deaths," U.S. President George W. Bush, who spoke by phone Tuesday with Zardari, said in a speech.
He did not specifically mention Washington's more aggressive moves of late in Pakistan - portraying the U.S. intentions as only to "help the government of Pakistan defeat Taliban and al Qaeda fighters hiding in remote border regions."
The unilateral actions have sparked a public backlash, including official protests, although it appears that Pakistan, the Islamic world's only nuclear power, is too dependent on the billions of dollars in U.S. aid to do much more than complain.
"We are very explicitly clear; we cannot tolerate civilian casualties," Karzai said, claiming that operations against militants have to be "foolproof."
"The war on terrorism will only be won if we have the people with us. To have the people with us, we must avoid civilian casualties."
But such operations are complicated. Militants often mingle with civilians. Troops in ground operations have more flexibility than drone-fired missiles, but such missions also carry risks of military casualties.
Many Pakistanis oppose their country's role in the war on terror, and blame it for fanning religious extremism. Pakistan Taliban have carried out a series of attacks, including a suicide bombing Saturday that killed at least 35.
The 53-year-old Zardari, whose wife was killed in a gun-and-bomb attack in December, is trying to convince them that the war on terror is their battle, not just Washington's.
While Zardari clearly wanted to take a strong stance on the issue, he quickly tried to separate himself with the increasingly autocratic methods that Musharraf employed.
When a reporter asked what he was going to do about one problem, Zardari smiled and suggested he should not be expected to run roughshod over Parliament.
"You are too used to a dictatorial president," Zardari said. He has vowed to return some of the powers to Parliament that were eroded under Musharraf, who took power in a 1999 bloodless military coup.
He said it would be up to legislators to decide whether to grant Musharraf indemnity from any criminal acts committed in office and suggested Parliament take strong action to prevent a food crisis like the one that devastated the poor when prices skyrocketed earlier this year.
Zardari said he already has been taking preliminary steps on jump-starting the peace process with India over the disputed region of Kashmir, saying he hoped to have "good news" by the end of the month.
Still, while he was looking at the future, there were constant signs of the past.
With his three children among the well-wishers and dignitaries packing a cavernous hall for the swearing in ceremony, Zardari beamed as the ceremony ended and shouts of "Bhutto is alive!" rang out.
He evoked Bhutto's name several times during the news conference, starting by saying he accepted the presidency in her name "and in the name of all the martyrs of democracy."