Rwanda's president, Paul Kagame, has rejected accusations from Washington that he was supporting a rebel leader and accused war criminal in the Democratic Republic of the Congo by challenging a senior US official to send a drone to kill the wanted man.

In an interview with the Observer Magazine, Kagame said that on a visit to Washington in March he came under pressure from the US assistant secretary of state for Africa, Johnnie Carson, to arrest Bosco Ntaganda, leader of the M23 rebels, who was wanted by the international criminal court (ICC). The US administration was increasing pressure on Kagame following a UN report claiming to have uncovered evidence showing that the Rwandan military provided weapons and other support to Ntaganda, whose forces briefly seized control of the region's main city, Goma.

"I told him: 'Assistant secretary of state, you support [the UN peacekeeping force] in the Congo. Such a big force, so much money. Have you failed to use that force to arrest whoever you want to arrest in Congo? Now you are turning to me, you are turning to Rwanda?'" he said. "I said that, since you are used to sending drones and gunning people down, why don't you send a drone and get rid of him and stop this nonsense? And he just laughed. I told him: 'I'm serious'."

Kagame said that, after he returned to Rwanda, Carson kept up the pressure with a letter demanding that he act against Ntaganda. Days later, the M23 leader appeared at the US embassy in Rwanda's capital, Kigali, saying that he wanted to surrender to the ICC. He was transferred to The Hague. The Rwandan leadership denies any prior knowledge of Ntaganda's decision to hand himself over. It suggests he was facing a rebellion within M23 and feared for his safety.

But Kagame's confrontation with Carson reflects how much relationships with even close allies have deteriorated over allegations that Rwanda continues to play a part in the bloodletting in Congo. The US and Britain, Rwanda's largest bilateral aid donors, withheld financial assistance, as did the EU, prompting accusations of betrayal by Rwandan officials. The political impact added impetus to a government campaign to condition the population to become more self-reliant.

Kagame is angered by the moves and criticisms of his human rights record in Rwanda, including allegations that he blocks opponents by misusing laws banning hate speech to accuse them of promoting genocide and suppresses press criticism. The Rwandan president is also embittered that countries, led by the US and UK, that blocked intervention to stop the 1994 genocide, and France which sided with the Hutu extremist regime that led the killings, are now judging him on human rights.

"We don't live our lives or we don't deal with our affairs more from the dictates from outside than from the dictates of our own situation and conditions," Kagame said. "The outside viewpoint, sometimes you don't know what it is. It keeps changing. They tell you they want you to respect this or fight this and you are doing it and they say you're not doing it the right way. They keep shifting goalposts and interpreting things about us or what we are doing to suit the moment."

He is agitated about what he sees as Rwanda being held responsible for all the ills of Congo, when Kigali's military intervention began in 1996 to clear out Hutu extremists using UN-funded refugee camps for raids to murder Tutsis. Kagame said that Rwanda was not responsible for the situation after decades of western colonisation and backing for the Mobutu dictatorship.

The Rwandan leader denies supporting M23 and said he has been falsely accused because Congo's president, Joseph Kabila, needs someone to blame because his army cannot fight. "To defeat these fellows doesn't take bravery because they don't go to fight. They just hear bullets and are on the loose running anywhere, looting, raping and doing anything. That's what happened," he said.

"President Kabila and the government had made statements about how this issue is going to be contained. They had to look for an explanation for how they were being defeated. They said we are not fighting [Ntaganda], we're actually fighting Rwanda."