By Jack Kimball

KAMPALA (Reuters) - Uganda's army urged the Democratic Republic of Congo and U.N. peacekeepers there on Wednesday to attack Ugandan rebels and force the guerrillas' elusive leader to sign a peace deal.

Kinshasa sent several hundred soldiers to a remote northern border region this week to try to box in fighters from Uganda's Lord's Resistance Army (LRA) and stop them attacking civilians.

Two years of talks between the group and Uganda's government collapsed in April after rebel leader Joseph Kony failed to emerge from the Congolese forest to sign a final peace agreement.

Kony is wanted by prosecutors at the International Criminal Court in The Hague for multiple war crimes committed during his 22-year rebellion in northern Uganda.

"What's true of Kony and the LRA is that they never engage in serious talks unless there's pressure behind them," Uganda's military spokesman, Major Paddy Ankunda, told reporters.

"The DRC (Congo) and (U.N. peacekeepers) MONUC should have dealt with these guys in June. We had cleared them to attack the

LRA."

Congo, Uganda and Sudan agreed a deal in June to launch a joint operation against the rebels, whose fighters have ravaged northern Uganda and destabilised neighbouring parts of oil-producing southern Sudan and mineral-rich eastern Congo.

Congo's military is expected to deploy around 2,000 soldiers with logistical support from the U.N. peacekeepers to Dungu on the edge of lawless Garamba National Park, which is a stronghold of Kony's forces.

But a spokesman for the rebels said the operation could damage peace prospects.

"This is the wrong approach, coming at the wrong time," chief LRA negotiator David Nyekorach-Matsanga told Reuters in the south Sudanese capital Juba.

Kony's rebels are notorious for chopping off limbs and abducting thousands of children in a rebellion that killed tens of thousands of people and displaced some two million more.

Earlier this year, LRA fighters in Garamba also raided Central African Republic, looting homes and abducting civilians.

MONUC, the world's biggest U.N. peacekeeping mission, has said it has no immediate plans to deploy peacekeepers directly in combat against the rebels.

In 2006, eight Guatemalan U.N. special forces troops were killed in a botched raid to capture or kill the then LRA deputy commander Vincent Otti in Garamba.

Ankunda accused the rebels of using the shaky peace to re-arm and abduct more recruits: "You can say that since they haven't signed the agreement, they are preparing for an attack."