* Brahimi says will press on with Syria peace efforts
* Says UN has no immediate plan to send peacekeepers
By Thomas Grove
MOSCOW, Oct 29 (Reuters) - International envoy Lakhdar Brahimi expressed regret on Monday at the failure of a four-day truce in Syria that he had arranged between President Bashar al-Assad's government and rebel forces.
Brahimi also said after talks with Russian Foreign Minister Sergei Lavrov in Moscow that there was no immediate plan to send U.N. peacekeepers to the Middle Eastern country.
"I am terribly sorry ... that this appeal (for a truce) has not been heard to the level we hoped it would, but that will not discourage us. It will not discourage us because Syria is very important and the people of Syria deserve our support and interest," he told a news conference.
"The government has made an announcement that they were going to stop fighting during the (holiday) and quite a few of the opposition groups did the same, so now each side is accusing the other of breaking the ceasefire," he said.
Hostilities barely paused during four-day Eid al-Adha Muslim holiday. Heavy air strikes and a car bomb hit Damascus on Monday, the last day of the ceasefire.
Asked whether the United Nations might send peacekeepers to Syria, Brahimi said: "There is no plan for the moment to send a peacekeeping mission, but just the contingency planning, because this may indeed become a possibility in the future."
Lavrov said Russia, which is a permanent member of the U.N. Security Council and which supported the truce, backed United Nations efforts to end the 19-month-old conflict in Syria and begin a political transition there.
Neither Brahimi nor Lavrov gave any clear indication of what next steps may be taken to halt the bloodshed.
Russia, together with China, has vetoed three U.N. resolutions aimed at pressuring Assad to end violence. Western countries say their stance has given the Syrian leader diplomatic cover to pursue his attempts to crush his opponents.
"We think this civil war must end ... and the new Syria has to be built by all its sons," Brahimi said. "The support of Russia and other members of the Security Council is indispensable."
The U.N.-Arab League envoy will visit Beijing after Moscow, China's Foreign Ministry said.