"It is very hard to double, it's a little bit tricky. I don't think I can take a risk to double so I am really working towards the 800," the 22-year-old said in a conference call from his African home on Thursday.

Rudisha will attempt to land his first world title at the August 27-September 4 world championships in Daegu, South Korea while also competing in the $50 million elite Diamond League 14-event schedule that starts on May. 6 in Doha and ends in September.

Rudisha broke Wilson Kipketer's 13-year record by 0.02 seconds in Berlin last August before bettering that with 1:41:01 a week later in the Italian venue of Rieti.

The effortless manner in which Rudisha sweeps around the track has led to talk of him breaking the elusive 1 minute and 40 seconds barrier.

"I said that as a possibility but it's not that easy and this year there are other things to concentrate on, the world championships being the priority," he said.

"After that I will see if I can do one or two fast races."

There are two Diamond League meetings after the biennial world championships, in Zurich on September 8 and September 16 in Brussels.

"This year I think I'm a little bit behind in my training, but I think I'm going to do well in Doha," Rudisha said, adding he would also run in Rome on May 26 and in the non-Diamond League Ostrava meet on May 31.

"I think Rome is a good place for a fast time," he said.

So far this year Rudisha has run 1:43:88 to retain his Melbourne Track Classic title last month.

The 1.90-metre Kenyan has never run in London and preferred not to think about the 2012 Olympics where he could emulate his father's silver medal in the 4x400 relay at the 1968 Mexico City games.

"We'll see when the times comes, I can't talk about that now," he said.