13. Deferred tax
 
  2018 
US$’000 
  2017 
US$’000 
 
Deferred tax assets 1 880    1 952   
Deferred tax liabilities (29 892)   (23 823)  
Net deferred tax liability (28 012)   (21 871)  
Deferred tax assets        
Property, plant and equipment (35)   (54)  
Unrealised foreign currency exchange losses 610    752   
Accrued leave 165    164   
Share-based payments 1 040    1 073   
Other 100    17   
  1 880    1 952   
Deferred tax liabilities        
Property, plant and equipment 63 212    57 765   
Tax losses not utilised (28 755)   (30 065)  
Accrued leave (3 573)   (1 977)  
Share-based payments (782)   (809)  
Other (210)   (1 091)  
  29 892    23 823   
Reconciliation of deferred tax liability        
Balance at the beginning of the year (21 871)   (3 878)  
Adoption of IFRS 16 (refer note 3) 7    –   
  (21 864)   (3 878)  
Temporary differences recognised in profit or loss and equity in relation to:        
   Capital allowances on property, plant and equipment (8 470)   (2 731)  
   Provisions 440    649   
   Tax losses (79)   (17 364)  
   Other 482    1 145   
  (7 627)   (18 301)  
Exchange differences 1 479    308   
Balance at the end of the year (28 012)   (21 871)  
Amounts recognised in:        
   Profit or loss (note 8) (7 933)   (19 162)  
   Equity 306    861   
  (7 627)   (18 301)  

Deferred tax assets and deferred tax liabilities are not offset unless the Group has a legally enforceable right to offset such assets and liabilities.

All of the above amounts have used the currently enacted income taxation rates of the respective tax jurisdictions the Group operates in. South African taxation losses normally expire within 12 months of the respective entities not trading. The deductible temporary timing differences do not expire under current taxation legislation. Deferred tax assets have only been recognised in terms of these items when it is probable that taxable profit will be available in the immediate future against which the respective entities can utilise the benefits therefrom.

The estimates used to assess the recoverability of recognised deferred tax assets include a forecast of the future taxable income and future cash flow projections based on a three-year period. The Group did not have tax losses and temporary differences for which deferred tax was not recognised.