President Barack Obama is deeply admired in Western Europe but his administration is less popular in Poland and other former Soviet satellites because of Washington's drive to mend ties with Russia - still deeply feared in the region - and plans to.
Biden's two-day visit to Poland, where he was to land Tuesday night, will be followed by stops in Romania and the Czech Republic.
The visit is seen by the Polish public and leaders as "mainly about damage control and trying to make up for mistakes," said Bartosz Wisniewski, a foreign policy analyst with the Polish Institute of International Affairs.
Obama in Septemberto put missile defense interceptors in Poland and a radar in the Czech Republic, a system intended to shoot down future long-range missiles from Iran.
The administration's planned replacement would instead be aimed against Iranian short- and intermediate-range missiles.
Obama has promised Poland and the Czech Republic the right to host elements of the new system. In particular, the U.S. has offered Warsaw the chance to host SM-3 missiles - the U.S. Navy's Standard Missile-3, an anti-ballistic missile that the Pentagon says is the most technically advanced and cost-effective way to counter Iran's anticipated arsenal.
Polish leaders in recent days have said they expect Biden to flesh out this offer during the visit.
But even hosting SM-3s would mark a scaled-down role for Poland in the U.S. missile defense system, a fact lamented by Polish President Lech Kaczynski and a host of political observers.
"Today we know one thing - Poland's role in the new plan will not be as big as the role it was to have in the Bush plan," Lukasz Kulesa, an analyst at the Warsaw-based Polish Institute of International Affairs, wrote Tuesday in the Gazeta Wyborcza daily.
He said the White House's new plan "does not give us an exclusive position," and that any SM-3 missiles that might be placed in Poland "will only be of secondary significance."
Poles were also dismayed that Obama announced his plans for a reconfigured missile defense system on Sept. 17, the 70th anniversary of the Soviet invasion of Poland at the start of World War II - timing that signaled to them a lack of sensitivity.
Kulesa said that, with Biden's visit, "The Americans are clearly trying to cover over the disastrous impression made by the manner in which the Americans presented their change to the missile defense on Sept. 17th."
Biden's national security adviser, Tony Blinken, said Monday that Obama's shift on missile defense, which was welcomed by Russia, does not threaten Poland or its neighbors.
"We've been very clear from day one that we are seeking to, but not at the expense of any of our partners," Blinken said.
Biden's stops in Bucharest and Prague come with both countries in political limbo.
The Czech Republic has a weak caretaker government that lacks the power to move forward on any missile defense deals.
In Romania, where a weak caretaker government also leads the country, three candidates campaigning for a November presidential election all hope to be given a boost by Biden's visit.
They "want to be taken notice of, to say 'look, we have America behind us,"' said Bogdan Chirieac, a Romanian political analyst.
But that state of limbo probably means Washington will hold off until after the election to initiate any significant new military or economic business with Bucharest, Chirieac argued.