"It's an opportunity for him and President Putin to continue what is always, for the two of them, candid and very honest conversations about things that matter," Bush spokesman Tony Snow said.

Bush's father, former President George H.W. Bush, has an oceanfront compound in Kennebunkport, and the two leaders will meet there.

The session comes at a time when many experts say relations between the two nations are at their lowest point since the Soviet era.

On Tuesday, Putin warned that the planned US missile shield for Europe would turn the region into a "powder keg."

Bush, Secretary of State Condoleezza Rice and Secretary of Defense Robert Gates have all tried to reassure the Russians that the missile system is aimed at preventing attack by a rogue state against the United States or Europe.

Washington and Moscow are also at odds over Kosovo, a province of Serbia that is under UN and Nato administration. Russia has called a Western-backed draft UN resolution that would endorse supervised independence for the Serbian province unacceptable.

Bush and Putin will discuss Iran, civil nuclear cooperation, missile defense and other issues, Snow said.

"Cooperation between the United States and Russia is important in solving regional conflicts, stopping the spread of weapons of mass destruction and combatting terrorism and extremism," Snow explained in announcing the visit.

The two leaders also will see each other next week in Heiligendamm, Germany, during the annual summit of industrialized nations.

Asked why Bush chose to hold the meeting at his father's house in Maine, Snow said, "Why not? It's a good place to have it."

Bush also has met with Putin at the presidential retreat at Camp David in Maryland's Catoctin Mountains. And, Putin was the first head of state to visit Bush's ranch in Texas in November, 2001. "You only invite your friends into your house," Bush said at the time.

Russia views US activity in its former sphere of influence with growing suspicion. Earlier this month, in a speech, Putin denounced "disrespect for human life, claims to global exclusiveness and dictate, just as it was in the time of the Third Reich."