Rebels in the east of the Democratic Republic of the Congo have said they are prepared to respond with "full force" to any attack by the United Nations' first offensive force.

In March the UN security council renewed the mandate of the UN mission in the Congo (Monusco) and approved the creation of a 3,000-strong "intervention brigade".

The force, which will include troops from South Africa, Tanzania and Malawi, will be equipped with an artillery unit and attack helicopters, and is intended to neutralise the year-long M23 rebellion and other armed groups in eastern DRC.

But Colonel Vianney Kazarama, the military spokesman for the M23 rebels, responded bullishly to the imminent arrival of the UN troops. "We are ready for this brigade," he told the Guardian at the M23 commando training camp in Rumangabo. "They will not know the terrain, our tactics, not even the local languages. It will take them weeks to organise. If they attack we will respond very quickly and with full force."

General James Mwakibolwa of Tanzania, who is to lead the UN brigade, has arrived in Goma, the capital of North Kivu province, which has been the theatre of combat with M23 since April 2012. Apart from him, however, there is no other sign of the UN force.

South African and Tanzanian troops and weaponry are on their way, according to Monusco officials, and are due to arrive in the next week. Soldiers from Malawi will bolster the force at an unspecified later date.

"There is no precise date [for the launch of operations by the brigade]," said Lieutenant Colonel Félix Basse, a Monusco spokesman. "They will be deployed as quickly as possible. We have to be realistic, the troops cannot arrive tomorrow and start operations the next day. They will need a period of familiarisation with their environment."

Despite the apparent delay in the deployment of the UN troops, M23 are preparing for their arrival. At the rebel base in Rumangabo, officers are undergoing training in attack, defence and ambush tactics as well as, improbably, kung fu.

During the interview with Kazarama the sound of bombs came echoing from the neighbouring Virunga national park, where M23 fighters were carrying out war games.

North of the training camp is Kiwanja, a town lying in the middle of M23 territory. Here there is a camp for internally displaced people, created five years ago during the last rebellion to unsettle the region. The highest ranking members of M23 also led that rebel group.

The locals are terrified of M23's intentions and want the fighters gone. But while civil society in Goma has eagerly welcomed the intervention brigade, people here worry that the UN's new aggressive stance will only exacerbate the conflict and their problems.

"We have lost so much, lost our belongings and our children already. If the new [UN] force arrives we'll just lose even more, we will die," said a woman who would not give her name for fear of reprisals by M23. "We have an African proverb: when two elephants fight, the grass gets trampled."

A camp elder, also unwilling to give his name, was sceptical of the force's capacity to put an end to M23. "There are 17,000 Monusco troops already in the Congo and there has been no change. How are you going to convince us that 3,000 soldiers will change the situation?"

Jason Stearns, Congo analyst and director of the Rift Valley Institute, a research organisation, was more positive about the potential influence of the force on stuttering negotiations between the rebels and the Congolese government. "Congo's government has long been plagued by a weak army which has led to endless negotiations," he said. "The brigade can act as a coercive force in the broader context of a peace process."

The presence in the brigade of South African and Tanzanian troops is significant, according to Stearns. These countries are politically and militarily influential in the region and, he says, can exert pressure on Rwanda – which has been widely accused of backing M23 – to use its sway over the rebels to dismantle the rebellion.

"Regardless of whether Rwanda continues to support M23, they supported them last year and continue to have influence over them," Stearns said. "South Africa and Tanzania will lash out at the Rwandan government if their troops are killed at M23 hands. If that helps bring M23 to heel, then it is positive."

The rebel delegation to peace talks hosted in the Ugandan capital, Kampala, have returned to M23 territory amid rumours they have abandoned the negotiations in protest at the UN's aggressive new mandate. However, the M23 president, Bertrand Bisimwa, denied those claims.

"We haven't quit the negotiations," Bisimwa said by telephone from the M23 capital, Bunagana. "What we want is for the government to agree to a ceasefire before talks resume. How can we talk when they are preparing war against us? There is no justification for this new UN force. A military approach to this problem will not work, the UN has said so itself. We need a political solution."

Mary Robinson, the new UN special envoy to the Great Lakes region, also emphasised the importance of political and diplomatic avenues during her visit to Goma on 30 April. "There's no doubt these armed groups have to be dealt with, but I think it's important that this does not become a focus on a military solution, [and] that we're implementing the political steps that have been committed to," she said.