Congo is planning to send up to 10,000 soldiers to its eastern province of North Kivu to prevent rebels and Rwandan forces from launching cross border attacks.
Over the last week, Rwanda has repeatedly threatened to send troops into Congo to target Hutu rebels, many of whom took part in Rwanda's 1994 genocide.
"We will be sending two or three brigades into North Kivu within two weeks," spokesman Kudura Kasongo said.
A Congolese brigade consists of roughly 3,200 soldiers.
"Firstly these people will be there to stop the Hutu rebels from launching an attack on Rwanda from the Congo. But we are also sending them there to contain the Rwandan aggression on our border. This is logical," Kasongo added.
Rwanda says neither Congo nor UN peacekeepers deployed in Congo have done enough over the past 10 years to deal with the rebels based in the jungles of Africa's third biggest country.
Congolese officials have branded Rwanda's threats a declaration of war and said the Kinshasa government might be forced to respond.
Rwanda's Foreign Minister, Charles Murigande, said Kigali was not unduly alarmed by Congo's troop deployment.
"It is their sovereign right to deploy their troops in their territory," he said. The rebels are known as the Democratic Forces for Rwandan Liberation (FDLR).
They include many members of the former army and Hutu militiamen who took part in the 1994 genocide, killing 800,000 Tutsis and moderate Hutus, before fleeing to Congo after they were defeated.
Since Rwanda threatened to attack last week, there have been several reports that hundreds of Rwandan troops have crossed into the former Zaire, although the UN mission there says it has no evidence of their presence.
Rwanda denies that its troops have moved into Congo. Rwanda has invaded Congo twice over the past eight years. The second invasion, in 1998, was one of the triggers for Congo's five-year civil war, which sucked in five other African neighbors and killed 3 million people, mostly through hunger and disease.
The FDLR is thought to number about 10,000 fighters scattered in the dense forests of North and South Kivu.
Rwanda officially withdrew all its troops from Congo in 2002 but there have been consistent reports of soldiers moving freely across the border. The area is also under the control of Rwandan-backed former rebel fighters from Congo's war.