"I'm contracted to September 2019 and that will see me out," he told the BBC.
England finished at 180 for nine off 88.1 overs as Australia won by an innings and 123 runs.
All four of Australia's front-line bowlers finished with 20 or more wickets each for the series.
Usman Khawaja plundered a big century as Australia roasted England's bowlers on Saturday to open up a 133-run lead with two days to play
At the close, Smith was on 44 with Khawaja reaching his highest score of the series on 91 in Australia's 193 for two
Skipper Root again missed out on an elusive first century in the series as Aussies struck late on the opening day of last Test
Root and Malan stole the highlights on the opening day of the SCG Test
Woakes has taken 10 wickets at 49.5 in the four Tests and scored just 114 runs through seven innings batting number eight at an average of 16.28.
Left-armer Starc is the leading wicket-taker in the series with 19 despite only playing three Tests
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Shane Watson continues his prime form in PSL
Lendl Simmons and Tymal Mills join Peshawar Zalmi
Most successful bowler in the history of PSL
Shadab vows to contribute more in upcoming matches
Multan Sultans pacer to feature in Euro T20 Slam
Dean Jones tears up while defending Asif Ali
Imam-ul-Haq joins the 'Yellow storm'
Dharmasena admits his 'error of judgment' in World Cup final
Solomon Mire quits international cricket