Standing alongside Vice President Joe Biden, Poland's prime minister said Wednesday his country was ready to participate in the Obama administration's revamped plan for a U.S. missile defense shield in Europe.

President Obama removed a major irritant in relations with Russia last month by scrapping U.S. plans to place 10 interceptor missiles in Poland and a radar in the Czech Republic to intercept long-range missiles from "rogue" states such as Iran. The Bush-era plan had enraged Moscow.

The Kremlin has praised Obama for the decision, but Russian officials also have said they want to know more about what missile defense system the U.S. will use instead.

Polish Prime Minister Donald Tusk welcomed the U.S. proposal for a missile shield that would replace a bulkier version previously planned for Poland.

"I want to stress that Poland views ... the new configuration for the missile shield as very interesting, necessary, and we are ready at the appropriate scale to participate," Tusk said at a news conference with Biden.

Biden, on the first stop of a three-nation trip aimed at reassuring Washington's allies in the region of its support, praised Warsaw for its readiness to accept the revamped plan. His trip was the highest-level visit yet by the Obama administration to Poland.

"We appreciate Poland has stepped up and agreed to host an element of the previous missile defense plan, and we now appreciate that Poland's government agrees with us that there is now a better way ... with new technology and new information, to defend against emerging ballistic missile threats," Biden said.

Biden said the new approach would meet "a growing threat" to the U.S. and Europe.

"It's going to meet it with proven technology that will cover more of Europe, including Poland, and will do it more efficiently than the previous system," he said. "Simply put, our missile plan is better security for NATO and is better security for Poland."

Biden arrived later Wednesday in Bucharest, where he was met by the U.S. ambassador to Romania, Mark H. Gitenstein. The vice president will meet Romanian President Traian Basescu and deliver a speech to students on regional security during his one-day visit Thursday.

He will travel to the Czech Republic on Friday.

Russian retired Gen. Viktor Yesin, the former chief of staff of the Russian military's Strategic Missile Forces, said Russia's reaction to the new missile defense plan will likely be calm unless the U.S. takes what he called provocative moves.

He said Moscow would certainly be angered if the U.S. were to send navy ships with interceptor missiles to the Black Sea or put a missile defense radar in Georgia.

Under Obama's new missile defense plan, U.S. Navy ships equipped with anti-missile weapons — such as the Navy's Standard Missile-3 — would form a front line of defense in the eastern Mediterranean. Those would be combined with land-based anti-missile systems to be placed on shore in Europe.

The proposal calls for a focus on short and medium-range interceptors to better counter expected threats from Iran. The Pentagon says the SM-3 anti-ballistic missile is the most technically advanced and cost-effective way to counter Tehran's anticipated arsenal.

Obama has said the old blueprint was scrapped largely because the U.S. has concluded Iran is less focused on developing the kind of long-range missiles for which the Bush-era system was originally developed.

All three of the ex-communist countries on Biden's trip have enjoyed cozy ties with the U.S. since Soviet-backed regimes fell 20 years ago. They have thrown their support behind Washington in its fight against terrorism, contributing troops to the U.S.-led war in Iraq and the NATO mission in Afghanistan.

Poland and Romania also face allegations of having hosted secret CIA prisons. Both deny the accusations.

Recently, regional leaders voiced nervousness that the Obama administration was ignoring the area's interests amid its push to reset relations with Russia — a power still deeply feared in eastern Europe.

Biden aims to reassure the region during his trip that Washington will not strike any deals with Russia over the heads of its allies.