Defense Secretary Robert Gates says the Bush administration is not willing to replace its plan for a missile defense system in Eastern Europe with Russia's counterproposal for a radar site in Azerbaijan.

That's the blunt message Gates was to deliver to Russian Defense Minister Anatoly Serdyukov during a private meeting Friday at the NATO gathering in Brussels.

Speaking to reporters Thursday, Gates said that despite strident Russian opposition, the U.S. will proceed with its plans for a radar system in the Czech Republic to watch for missile threats and 10 interceptor rockets in Poland to shoot down any missiles.

Gates dismissed any notion that Russia's push for joint use of a radar station in Azerbaijan could replace the broader U.S. plan. And he expressed doubts that there could be any agreement with the Russians by next month, when President Bush is scheduled to meet with Russian President Vladimir Putin at Kennebunkport, Maine.

"I was very explicit in the (NATO) meeting that we saw the Azeri radar as an additional capability, that we intended to proceed with the X-Band radar in the Czech Republic," Gates said during a press briefing.

Gates' comments came as Russian officials called for a freeze on the U.S. plan, arguing that it would undermine Russia's nuclear deterrent. Russian officials reportedly issued threats against the planned sites in Poland and the Czech Republic. Gates said Serdyukov, who was at the NATO meeting, did not comment on his remarks.

Meanwhile, NATO ordered its military experts to draw up plans for a possible short-range missile defense system to protect nations on the alliance's southern flank that would be left exposed by proposed U.S. anti-missile units in central Europe.

According to U.S. and NATO officials, the addition of the European bases to anti-missile installations in North America would protect most of Europe from the threat of long-range attack from Iran or elsewhere in the Middle East. But it would leave Turkey, Greece, Bulgaria and parts of Romania exposed.

To fill that gap, NATO Secretary General Jaap de Hoop Scheffer said NATO experts would produce a report by February on short-range anti-missile defenses "that can be bolted on to the overall missile defense system as it would be installed by the United States."

Russia has threatened to retaliate against the U.S. plans by pulling out of a key arms control treaty and pointing warheads at Europe for the first time since the Cold War. However, at last week's G-8 summit, Putin seemed to take a more open approach, suggesting Russia could cooperate with the West on an anti-missile radar base in Azerbaijan.

The NATO ministers also were due to meet their Afghan counterpart Friday. The defense ministers were seeking to increase training for the Afghan military and reduce the rising toll of civilian casualties in Afghanistan.

Gates urged European allies to stick to commitments to contribute equipment and troops to the 36,000-strong NATO force in Afghanistan. He also complained about "shortfalls in key capabilities" that are affecting the Afghan fight, including delays in getting more transport aircraft and the low level of military spending by some allies.

There are about 26,000 U.S. troops in Afghanistan.