The United States, France and Britain said Thursday that they "remained united" in their determination to see Moammar Kadafi relinquish power in Libya, even as a meeting of the North Atlantic Treaty Organization in Berlin heard a top commander appeal for more ground attack aircraft to bolster the alliance's efforts against Kadafi's forces.
Secretary of State Hillary Rodham Clinton sought to smooth over tensions among NATO members, saying that Kadafi "is testing our determination.... As our mission continues, maintaining our resolve only grows more important."
Her words were backed by a joint declaration issued hours later by President Obama, British Prime Minister David Cameron and French President Nicolas Sarkozy, promising to sustain their military operations in Libya.
Clinton said the United States was "especially concerned about the atrocities unfolding in Misurata," according to news accounts. "We are taking actions to respond, and those responsible will be held accountable."
But NATO chiefs say they need more ground attack aircraft to be more effective.
U.S. Navy Adm. James G. Stavridis, NATO's supreme allied commander, Europe, said at the meeting of foreign ministers that eight additional, specific warplanes were necessary for precision strikes against Kadafi's units without causing civilian casualties, according to U.S. and NATO officials.
It was unclear which nations within the alliance might respond to the request. The U.S., which has far more ground attack planes than any other country, withdrew them last week when it shifted to a support role. And no other countries have so far pledged to meet Stavridis' request, the officials said.
Britain and France have openly insisted over the last few days that more action from the U.S. is needed.
Libyan forces have continued to attack opposition-held areas in the last week, but many have shed their uniforms and hidden their armored vehicles to avoid being targeted by NATO's high-flying and fast-moving fighter jets.
Only the U.S. Air Force has A-10s or AC-130s, planes that fly lower and slower to carry out precision attacks on ground targets.
Several other NATO members have fighters that have been modified to conduct such attacks, including the Netherlands and Britain, a U.S. officer said. Britain has already provided several Tornado ground attack fighters and said it would modify two Typhoon aircraft for a ground attacks.
But "many countries have ground-strike assets that have not been offered to the Libya campaign," the NATO officer said.
There was no sign that the United States was considering making its A-10s and AC-130s available.
Canadian Air Force Lt. Gen. Charlie Bouchard, commanding the Libyan campaign, has not asked for the U.S. warplanes and would do so only in an "emergency," the NATO officer said.
Times staff writer Borzou Daragahi in Beirut contributed to this report.