NAIROBI (Reuters) - Kenya's inflation rose to 6.39 percent year-on-year in July from 5.80 percent the previous month, the statistics office said on Friday. Policymakers held the benchmark lending rate on Monday at 10.50 percent saying this month's increase in the fuel tax would put temporary upward pressure on inflation. The statistics office said the transport index went up 1.13 percent in July on the back of the increases in the prices of petrol and diesel. Although the costs of some food items went down, they were outweighed by a jump in prices of others, driving up the good and non-alcoholic drinks index by 1.12 percent, the statistics office said. (Reporting by Duncan Miriri; Editing by Alison Williams)