Sri Lanka, Oct. 12 -- Former US President Joe Biden is receiving radiation therapy as part of his treatment for prostate cancer, his spokesman has said.

The spokesman also said that Biden, 82, was undergoing hormone treatment, without giving any further details.

The radiation treatment was expected to span five weeks and marked a new point in his care, a source told NBC News.

In May, Biden's office announced that he had been diagnosed with a more aggressive form of the disease, which had spread to his bones. The discovery came after the Democratic politician reported urinary symptoms that led doctors to find a small nodule on his prostate.

The Biden office said at the time that "he was diagnosed with prostate cancer, characterised by ...