PORTLAND, Maine — Russian leaders gave three U.S. senators an earful on the Bush administration’s proposed missile defense in advance of their travel to Poland and the Czech Republic, where the missile launchers and radar would have been located, Sen. Susan Collins said Tuesday.

The Russians want better relations with the U.S., but remain convinced that the missile defense shield targets their country and not a potential threat from Iran, Collins said.

“They are convinced that those installations are directed at them. Despite our assurances that it’s directed at the threat from Iranian missiles, they remain convinced it’s a threat against them,” she told The Associated Press by phone before departing for Poland and the neighboring Czech Republic.

Collins, a member of the Armed Services Committee, was traveling with fellow committee member Bill Nelson of Florida and committee Chairman Carl Levin of Michigan.

Missile defense was one of several topics on which Foreign Minister Sergey Lavrov and Deputy Foreign Minister Sergei Ryabkov raised concerns with the U.S. delegation. Others included NATO’s expansion, climate change and Russia’s treatment under the Bush administration, Collins said.

Collins described the Russians as “consumed by a sense of grievance and resentment and a loss of power that shades their views on virtually every issue.”

“Nevertheless, I leave hopeful that they clearly want to re-establish better ties with our country,” she said. “I think they are having a hard time coming to grips with the fact that there’s no longer two superpowers in the world, and it has been a difficult adjustment for them.”

The U.S. delegation also met with the chairman of the International Relations Committee of Russia’s Duma and with a human rights activist who spent years in a Soviet prison.

But the primary focus was national security issues.

Collins said she supports missile defense but remains open to the potential sites. The issue will likely go before the Senate Armed Services Committee later this year, she said.

The Bush plan called for putting 10 missile launchers in Poland and radar dishes at a military base outside Prague. The Obama administration is reviewing the proposal.