Short Term Profit (within 6 months) from US Treasury Bill is Interest Income or Capital Gain

A purchase of US Treasury Bill under par at 98.36 by paying USD9,836.00 on 30 April 2024 and USD10,000.00 will be credit into investment account on the maturity of 22 August 2024. Could you advise the profit of USD164.00 is subject to Interest Income Tax or Capital Gain Tax? For the purchase transaction, a brokerage charges of USD5.00 was paid to investment broker, may I claim this charges as cost of transaction? If the cost of transaction may be claimed, should the net profit (i.e USD164 - USD5) of USD159 to be submitted in the Self Assessment Tax Return? or else

Hi Cain,
US government bonds, sometimes known as T-bills or treasury bills are generally taxed as income rather than Capital Gains.  The return is paid at maturity rather than regular interest payments.  In the UK, these are known as deeply discounted securities, with the discount being the difference between the price at which they were issued and the price received at maturity.  On a foreign investment the income is the difference between the purchase and redemption price after each has been converted to sterling on the day the transactions took place, so includes any foreign exchange gains.  Losses cannot be deducted. 
Have a look at SAIM3010 - Deeply discounted securities: introduction for more information.
Thank you.