Well-placed sources in the Afghan and U.S. capitals familiar with the scope of Biden's talks with the Afghan president told RFE/RL that it appeared he did deliver a strong message to Karzai. But they said it included no mention of the end of Karzai's presidential run, over which the United States in any case has no say.
The streets of Kabul were filled with rumors about the implications of Biden's visit there on January 10, including talk of another "regime change" seven years after U.S.-led military strikes led to the collapse of Afghanistan's hard-line Taliban regime.
Karzai was the compromise choice to head the UN-backed government that replaced the Taliban, and was elected president in a popular vote under a new constitution in 2004.
But this is an election year in Afghanistan, and many Afghans are looking favorably at the prospect of a presidential change given rising insecurity in the country, endemic corruption within Karzai's administration, and a widening gulf between the rich minority and poor majority.
Speculation in the wake of Biden's visit was fueled in part by critics who hold senior posts in Karzai's own administration. Among the comments that circulated in the Afghan capital were that Biden flatly told Karzai he was on his way out, and that the incoming U.S. vice president's visit to the Afghan Interior Ministry during his stopover was really an effort to find a suitable replacement.
Interior Minister Mohammad Hanif Atmar is tipped by some to be a possible presidential candidate, and Biden's visit with him was seen by some observers as a significant gesture.
The Karzai-Biden meeting in general was depicted by the sources familiar with its substance as one intended to improve bilateral cooperation that was conducted by a long-serving chairman of the Senate Foreign Relations Committee.
Based on interviews with those sources, it appears Biden stressed to Karzai that he needs to rid his government of corruption and mismanagement. Karzai's growing criticism of U.S. military strategy -- particularly its reliance on air strikes that frequently result in civilian casualties -- also entered the discussion, and the Afghan president was reportedly told that Washington will view future such statements as posturing for the presidential elections set to take place in Afghanistan later this year.
Atmar, the British-educated interior minister, is widely considered one of the most effective managers in Karzai's administration, but he downplayed rumors that Biden's visit to his ministry represented a wink or nod regarding a possible presidential bid.
Atmar told RFE/RL's Radio Free Afghanistan that Biden's visit simply reflected protocol for visiting foreign lawmakers.
"Usually when senators [and other lawmakers] from the U.S. and other countries visit us, we meet them in our offices -- perhaps one can speculate that he was thinking that he is not yet the vice president and was here as a senator; so he chose this protocol for himself and came to my office," Atmar said. "But the most important thing is that Biden promised us strongly that he will help the Afghan police forces."
A Need To 'Review Our Strategy'
Karzai's spokesman, Humayun Hamidzada, stressed the positives of the meeting, emphasizing that Biden met Karzai as a U.S. senator and that it should not be taken out of its proper context.
"There was frank but cordial and friendly conversation with the president. They discussed all aspects of our relationship with the U.S. and both sides, of course, agreed that we need to work together and continue the partnership," Hamidzada said. "We are going through a difficult time. The president [Karzai] has said on a number of occasions that we need to review the war on terrorism. We need to review our strategy -- the way we fight terrorism and where we fight terrorism."
"The president discussed in minute detail the issues of corruption, the issues of governance, the issues of the management of the international aid, and the issues of the civilian casualties, which is very high on the Afghan agenda," Hamidzada said.
Hamidzada said the meeting ended on a positive note, with both sides agreeing to continue their conversation "to find a mechanism for a more effective partnership."
That conclusion, however, is bound to be contested by Karzai critics.
Outspoken Afghan parliament member Shukaria Barakzai told Radio Free Afghanistan that the future relationship between Kabul and Washington remains uncertain despite promises from the incoming administration of President-elect Barack Obama to commit more U.S. troops and aid to Afghanistan.
"There are a lot of rumors and people are talking about all kinds of speculation," Barakzai said. "But the clear thing is this: The new U.S. administration and the current Afghan administration will not be speaking a common language -- and Washington and Kabul will not be as close as before."
In Washington, former Obama campaign adviser on South Asia Marvin Weinbaum agrees with that assessment.
Currently a scholar-in-residence at a Washington-based think tank, the Middle East Institute, Weinbaum maintains that in an Afghan election year, the Obama administration should make it clear to Karzai that they are not "four-square behind him."
He says the success of planned changes in the military strategy and a renewed focus on Afghanistan's reconstruction requires that the Karzai administration restore the confidence of Afghans in its ability to serve them.
"The improvement in the functioning of the Karzai administration is critical to the success of the other policy changes, including military and development assistance changes," Weinbaum says, "and that, without those changes, it will undermine the success of those other initiatives."
In addition to Afghanistan, Biden's tour took the incoming vice president to Pakistan and Iraq.
RFE/RL Radio Free Afghanistan deputy director Hashem Mohmand and correspondents Ahmadullah Takal and Fareshta Jalalzai contributed to this story