"We cannot keep hosting refugees," from DRC, Rwanda President Paul Kagame told the upper house of parliament in the capital Kigali.
"This is not Rwanda's problem. And we are going to ensure that everybody realizes that it is not Rwanda's problem," he vowed.
"I am refusing that Rwanda should carry this burden," he said.
In November, the UN said around 72,000 people from DRC had crossed into Rwanda.
Persistent fighting in the east of the mineral-rich DRC pits federal troops against rebels from the M23 group, which has captured swathes of territory.
The DRC, along with the United States and several European countries, has repeatedly accused Rwanda of backing the Tutsi-led rebels from M23, although Kigali denies the charge.
Tensions have soared and thousands have fled the battles into neighboring states, including Rwanda.
Kigali has repeatedly blamed Kinshasa for the crisis and accused the international community of turning a blind eye to DR Congo's alleged support for the Democratic Forces for the Liberation of Rwanda (FDLR), a mainly Rwandan Hutu rebel movement implicated in the 1994 genocide of Tutsis in 1994.
Kigali sees the FDLR as a threat which justifies incursions into the DRC.
Rwanda has also accused the DRC -- where presidential elections are due next December -- of using the conflict for political purposes as well as of "fabricating" a November massacre of at least 131 civilians.
A UN probe blamed the deaths on M23 rebels.
A tentative ceasefire and the deployment of Kenyan forces through the East African Community (EAC) have so far failed to halt the bloodshed.