MOSCOW — President Dmitry Medvedev said Friday that Russia will still deploy missiles near Poland if the United States pushes ahead with a missile shield in Eastern Europe.

Medvedev reaffirmed the threat four days after he welcomed Obama to Moscow for a summit aimed at improving troubled ties.

Medvedev and Obama reached a preliminary agreement on new reductions in the Russian and American nuclear arsenals. Russian officials have suggested Moscow may not sign a treaty on the cuts unless the U.S. abandons the previous administration's plans for missile defense facilities in Poland and the Czech Republic.

Medvedev said the Kremlin believes the Bush administration's decision to build those facilities was "a mistake."

"If we cannot agree on these questions, you know the consequences," he told a news conference at the Group of Eight nations' summit in L'Aquila, Italy.

"What I said in my (state of the nation) address — I have not withdrawn this idea," he said.

He first made the threat in a state-of the-nation address just hours after Barack Obama was elected in November.

The new remark appeared aimed to stake out a firm position ahead of further talks with the U.S. on an arms reduction deal to replace the 1991 START I treaty, which expires in December. At the same time, his use of the word "revise" — rather than something more unequivocal — appeared to leave the door open for further bargaining on missile defense.

Medvedev praised Obama for ordering a review of the missile plans, saying that made him feel "moderately positive" that the U.S. will abandon the idea.

"Whose point of view will prevail in the American administration, I do not know," he said.

During the Moscow summit Monday and Tuesday, Obama reiterated the U.S. insistence that the missile defense system would pose no threat to Russia. U.S. officials say they intent would be to guard against a potential missile threat from Iran, but Russian officials say they fear its real intent is to weaken their country's nuclear deterrent.

Medvedev made more upbeat comments about his first summit with Obama. He called the agreements reached "very, very positive," particularly compared to Russian-U.S. ties about six months ago, which he said had "rolled back almost to the level of the Cold War."

Russian-American ties, severely strained during the presidencies of Vladimir Putin and George W. Bush, were further damaged by Russia's war with U.S.-supported Georgia last August.

Medvedev said he and Obama are getting along well, adding: "I like talking to Barack."

"I won't hide the fact that last year, it was harder for me to talk with the president of the United States of America, as our positions on many issues differed," Medvedev said. "More accurately, I'll put it this way: Talking with the younger George Bush is a real pleasure — he is a sincere person, a quick-witted person — but unfortunately this had no consequences for our relations; frankly speaking, it sometimes had negative ones.

"In this sense, I hope that Barack Obama and I listen to each other better and understand each other better, too," he said.