NATO foreign ministers wrapped up two days of talks in Berlin still divided on ways of intensifying the air campaign on Libya.
NATO foreign ministers offered a show of unity in calling for the departure of Libyan leader Moammar Gadhafi, but they ended their meeting in Berlin still apparently at odds over ways to add to their Libyan air operation.
The leaders of the U.S., France and Britain published a joint opinion piece in several newspapers Friday saying a future with Mr. Gadhafi in power was unthinkable. They said NATO operations must continue so long as the Libyan leader remained in power to protect civilians and keep up the pressure against the Libyan regime.
NATO Secretary General Anders Fogh Rasmussen reacted to the letter at a final press conference Friday afternoon.
Listen to VOA Middle East Monitor host Susan Yackee's interview with Robert Powell, Mideast analyst for "The Economist Intelligence Unit":
"On the letter from President Obama, President Sarkozy and Prime Minister Cameron, I think the letter reflects the unity of purpose and determination of NATO allies - exactly the unity we expressed yesterday in our Libya statement," said Anders Fogh Rasmussen.
But only half of the 28 NATO members are actively participating in the airstrikes. France and Britain, which have taken leading roles in the operation, are calling on other NATO members to do more.
Following talks with Secretary State Hillary Clinton, British Foreign Secretary William Hague said the two saw "eye to eye" on what was required in the Libya campaign.
"..on the whole strategy going forward on which other nations we would like to step up their efforts and we are working together very closely on that," said William Hague.
For his part, French Defense Minister Gerard Longuet suggested a stronger United Nations resolution might be needed to stem the violence in Libya - although he appeared skeptical about the chances of getting one.
In remarks to French television channel LCI, Longuet also said the statement by the three world leaders was a signal to Libyans there was no future with Gadhafi.
But Russia, meanwhile, warned the alliance on Friday against excessive force and said NATO is going beyond the United Nations mandate to only protect citizens.
NATO ministers also discussed Afghanistan, and held meetings with counterparts from Georgia, Russia and Ukraine.