Question about the juristiction of the International Criminal Court?

I am currently looking up about the DRC's Bosco Ntananda. He is leader of the National Congress of the Defense of the People (Congolese Rebel group), though they have now become integrated into the national army and he is acting as a General.

Ntananda has an arrest warrant out for him for evidence of his crimes such as murder, massacre, kidnapping, etc. (at least 16 separate counts), but the Congolese government has decided not to execute the warrant, because of "peacekeeping" purposes. This basically means that they do not want to arrest him because he is the only person keeping the rebel group on the government's side I think.

I have two questions:

1) Sure this is illegal by the Congolese government right? Do they not have a duty to execute the warrant?

2) Does the ICC not have authority to have some group of forces (I'm guessing they'd use the UN army) to go into DRC and execute the warrant?

Thanks so much for any help