Obama ratchets up pressure on Gadhafi; Russians object

Tripoli, Libya (CNN) — As U.S. President Barack Obama warned Libyan leader Moammar Gadhafi Wednesday that there would be “no letup” in NATO airstrikes, Russia lashed out against the air campaign, calling the bombing of certain Tripoli targets a “flagrant deviation” from the United Nations mandate.

The U.N. chief said Wednesday he had spoken with the Libyan prime minister and stressed the urgent need for a ceasefire.

Secretary-General Ban Ki-moon said the special U.N. envoy for Libya, who has been in Benghazi meeting with the Libyan opposition, would be returning to Tripoli soon to try to secure an agreement.

The war has dragged on for many weeks, with reports of horrific fighting and civilian casualties.

The Russian Foreign Ministry alleged Wednesday that several “non-military facilities in Tripoli that had already been bombed, were again attacked in a massive NATO airstrike, leading to civilian casualties.” It said in a written statement that “this is yet another flagrant deviation” from the U.N. Security Council resolution 1973.

That resolution authorized all means necessary, short of occupying forces, to enforce a no-fly zone and protect Libyan civilians from attacks by forces loyal to Gadhafi.

A barrage of at least 18 rockets struck Tripoli Tuesday, killing 19 people and wounding another 150 in the heaviest onslaught since NATO’s aerial strikes began, a government official told CNN.

NATO said it had struck a government vehicle storage facility adjacent to Gadhafi’s compound.

The Russian ministry said NATO has justified its attacks with the need to protect civilians but said that it was “impossible to deny the obvious fact that airstrikes are not stopping military confrontation between the warring Libyan sides, and are only causing additional suffering of peaceful Libyans.”

It said the airstrikes are failing to bring closure to the Libyan conflict, triggered by protests in February and an ensuing crackdown by Gadhafi’s forces.

Russia, which has been critical of NATO airstrikes all along, believes normalization in Libya can only come from an immediate halt in military activities, the ministry said.

Some have viewed the Libya campaign as a litmus test for relations between the alliance and Russia. The 28 members of NATO work with Russia as equal partners in the NATO-Russia Council, a group that works on a wide array of issues including security.

Obama, who held meetings with his British counterpart David Cameron in London Wednesday, increased pressure on Gadhafi by saying that ultimately, the embattled strongman had to go.

The mission to protect Libyans from their leader means making sure Gadhafi “doesn’t have capacity to send in a bunch of thugs to murder innocent civilians and threaten them,” Obama said.

“I do think we have made enormous progress in Libya. We have saved lives. Gadhafi and his regime need to understand there will not be a letup in the pressure we are applying,” Obama said.

But both he and Cameron said it will take time to reach a solution in the North African country, ruled with an iron fist by Gadhafi for 42 years.

“We may have to be more patient than people would like,” Obama said of the seeming stalemate in the war.

In an effort to break the months-long standoff, South Africa President Jacob Zuma plans to visit Tripoli next week for talks with Gadhafi, according to a statement on the South African leader’s website.

Zuma will meet Gadhafi Monday in “his capacity as a member of the African Union high level panel for the resolution of the conflict in Libya,” the statement said. The panel also includes Uganda and Mauritania.

It is the second trip for Zuma, who was part of an African Union delegation that visited the nation last month. That visit included talks on a cease-fire, which did not succeed.

The Libyan government, meanwhile, lashed out at Obama and Cameron.

“It is illegal and illegitimate to speak about regime change under the pretext of protecting civilians,” said a government official. “It is up to the Libyan people to decide when and if Colonel Gadhafi should go — not the U.S. and the UK.”

Russia’s official RIA Novosti news agency reported that Gadhafi’s government may ask Moscow to mediate the conflict.

CNN’s Nima Elbagir contributed to this report.