Intensifying tensions between the two nations, White House spokesman Robert Gibbs said that a series of critical comments by Karzai was "troubling" and "confusing.”
Pressed to say whether the May 12 meeting might be called off, Gibbs told reporters: "We certainly would evaluate whatever continued or further remarks President Karzai makes, as to whether that's constructive to have such a meeting." Among comments that have angered his backers, Karzai accused embassies of perpetrating election fraud in Afghanistan last year and of seeking to weaken him. He told tribal elders on Sunday that government officials should not let "foreigners" interfere in their work.
Asked whether Karzai was still viewed as an ally of the United States after those comments, Gibbs replied: "Karzai is the democratically elected leader of Afghanistan." Initially the Obama administration sought to play down Karzai's comments saying they were aimed at placating his domestic audience. But in recent days, Gibbs and others have taken a tougher line.
"We will not hesitate to ensure that the remarkable investment that our men and women are making is met with the type of governance that has to be in place in order to secure parts of a dangerous country," said Gibbs.
The White House earlier said it was frustrated on behalf of the American public, and invoked the sacrifice made by families who send their loved ones off to fight in the Afghanistan war.
There are more than 120,000 Western troops in Afghanistan, including more than 80,000 Americans, set to rise to 100,000 Americans this year.
Karzai's anti-Western tone was particularly embarrassing for the White House as it came days after Obama made his first trip to Afghanistan since he took office in January 2009.
During that trip, Obama pushed the Afghan government hard on tackling corruption, a longtime irritant for Washington.
Karzai's outbursts have also raised the hackles of US lawmakers whose support is crucial to fund the war effort.
Prominent Democratic Representative Jane Harman added to a chorus of complaints, telling Reuters that Obama should reassess whether Karzai was a "willing partner" needed for his counterinsurgency strategy to work.
"Karzai's recent comments are extremely troubling and I am personally very disappointed in his effort to control corruption in his country," said Harman, chairwoman of the House of Representatives Homeland Security Subcommittee on Intelligence.
She added: "I'm somewhat skeptical we can achieve our objectives in Afghanistan." Karzai has sought to ease tensions with the Obama administration, calling US Secretary of State Hillary Clinton last Friday to clarify his remarks but not to apologize. Two days later, he made more disparaging comments.
