White House officials say they do not expect U.S. President George W. Bush and Russian President Vladimir Putin to reach an agreement this weekend on a missile defense system that the U.S. wants to place in Central Europe. 

The U.S. and Russian leaders are meeting in the Black Sea resort of Sochi, where the U.S. missile defense plans are on the agenda.  A White House spokeswoman traveling with the President said the talks were on the right track, but more work will be needed after Sochi.

The proposed missile defense system would be placed in Poland and the Czech Republic.  The U.S. says it is intended to protect Europe from missiles that Iran is developing.  Russia strongly opposes the plan and has said it is a threat to its security. 

Mr. Bush arrived in Sochi from Croatia, where he stopped after this week's NATO summit in Bucharest, Romania.

In his weekly radio address Saturday, the President saluted the progress Croatia has made in the past ten years, which has allowed it to receive an invitation to join NATO.

"Since they attained their independence, the Croatian people have shown the world the potential of human freedom," he said.  "They've overcome war and hardship to build peaceful relationships with their neighbors.  And they have built a maturing democracy on the rubble of a dictatorship.  This week NATO invited Croatia, as well as the nation of Albania, to join the NATO alliance.  These countries have made extraordinary progress on the road to freedom, prosperity and peace."

NATO leaders invited Croatia and Albania to begin talks toward alliance membership.  President Bush said he regrets that Macedonia did not get an invitation, because of a dispute with Greece over the country's name. 

Ukraine and Georgia, despite U.S. lobbying for them, also failed to win an invitation.

Here in Washington, Delaware Senator Joe Biden gave the Democrats' weekly radio address.  Biden concentrated on the war in Iraq, where he says the U.S. military, despite its best efforts, is only "treading water."

"Folks, I believe the President has no strategy for success in Iraq," he said.  "I believe his plan is to muddle through and hand the problem off to his successor.  Well, our troops and their families deserve a lot better than that.  We owe them a strategy worthy of their sacrifice.  We Democrats understand that this war must end."

Biden acknowledged that violence in Iraq has decreased, but he said the government in Baghdad has made little political progress, and that there's little evidence that Sunnis, Shi'ites and Kurds will settle their differences peacefully any time soon.