1997 Mitsubishi Pajero Mini 660cc Dohc 20 Valve Inter Cooler Turbo Recently

I have Pajero Mini 660cc, DOHC 20 valve with inter-cooler turbo. Recently I have been noticing that my car emits white smoke whenever I press the gas a bit harder for higher acceleration. Alongwith this problem I have also noticed reduced power. Previously my car was touching the speed upto 130kph, whereas now it's not moving ahead of 100kph. Apart from these 2 things I have not noticed any unusual thing in my car's drive. I have recently put new spark plugs and replaced automatic transmission fluid as routine maintenance.
Kindly help me out.