Rwanda has been told by the United Nations Security Council that the world is monitoring its actions in the Democratic Republic of Congo, where it backs a rebel group that is in violation of a ceasefire.
Kagame was tough with the visiting delegation
Security Council ambassadors visited Rwanda as part of a tour of central Africa, during which they are trying to end the conflict in DR Congo which is estimated to have cost three million lives over the past decade.
Rwanda occupied part of eastern DR Congo until last year and several African states accuse it of still having troops there, though Rwanda denies this.
The Rwandans say they originally sent troops to DR Congo to stop rebels that threatened them from bases beyond their border.
They say their soldiers were all pulled out last year, but the DR Congo Government says Rwanda is still present and illegally exploiting the mineral riches in the east of the country.
A Rwandan official, Patrick Mazimhaka, said DR Congo was making excuses for its own failings.
"It is in their interests. The Congolese must find an external enemy to justify why they are failing to set up the process they agreed. So that's why they are doing it," he said.
The UN agrees that several groups are violating the ceasefire in DR Congo but thinks Rwanda's co-operation is absolutely key to a solution.
But while the Security Council may urge Rwanda to co-operate, it is not threatening any sanctions to make it act.
And the Rwandan President, Paul Kagame, was characteristically tough with the visiting diplomats.
Referring to the Congolese rebels Rwanda has used to create a buffer-zone against anti-Rwandan government forces in Congo, Mr Kagame said - according to sources at their meeting - "Thank God they're there, because if they were not we would have to do the job."