Brende was in London on Wednesday for his first official meeting with British Foreign Secretary William Hague.
"The political system in Congo is complex, but I feel that we will be in a much stronger position if we coordinate with William Hague and the United Kingdom. It gives us extra weight if we can work together," Brende told Norway's TV2 channel.
The 31-year-old French, and his friend and fellow inmate Tjostolv Moland, were sentenced to death for murder and spying in 2010.
Moland who was found dead in the cell they shared in August, giving the case new urgency, particularly as Congolese authorities have openly considered pinning the blame on French.
French was on November 13th interviewed once again by the Congolese police over the death, despite an initial autopsy report which concluded that Moland took his own life.