Sixty-nine percent of the public oppose the war in Iraq, while another 62 percent oppose the war in Afghanistan, according to the latest CNN poll.
Both conflicts have become more unpopular since May, when 62 percent objected to U.S. involvement in Iraq, and 56 percent said the same about Afghanistan.
Growing impatience with the developments in both countries has led a majority to support President Obama's plan for a troop drawdown in July 2011, a move Gen. David Petraeus has said must be "conditions-based."
"We are doing everything we can to achieve progress as rapidly as we can without rushing to failure," Petraeus told The Washington Post. "We fully appreciate the impatience in some quarters."
Meanwhile, other officials have noted that the new strategies recently implemented in Afghanistan need time in order to begin working.
Another challenge for Afghanistan lies in a political system that is weakened by corruption and voter fraud.
Sen. John Kerry (D-Mass.), chairman of the Foreign Relations Committee, said during a visit to Kabul on Tuesday that the challenges represent a "test" for Afghan leaders.
"That's why I'm here," Kerry noted, "because I think President Karzai and his government need to understand that there is no patience for endless support for something that doesn't meet higher standards with respect to governance."
Kerry also said that he was glad to see the government take steps — creating an anti-corruption task force, for example — to root out its problems.
"I think under the circumstances we need to work closely with the president in the next weeks and days to set up a series of very specific goals [for progress]," he said.
Despite talk of these steps, a majority of the public lacks confidence in the governments of both Afghanistan and Iraq to succeed after U.S. withdrawal.
Voters also doubt that withdrawal could endanger Americans: only 28 percent believe that leaving the conflicts would make the U.S. more vulnerable to terrorist attacks, a mainstay reason for military involvement in the first place.
In Kabul, Kerry addressed growing public concern.
"I understand the impatience but impatience is not a strategy and impatience doesn't meet the security needs of our country," he said.
Obama has planned a major war strategy review for December.