Observational and modeling studies have elucidated the influential role played by the southern and northern extratropical Pacific (SEP and NEP) forcing in shaping the dynamics of tropical Pacific climate variability. However, the relative importance of the NEP and SEP and the timescale on which they impact the tropics remain unclear. Using a linear inverse model that selectively incorporates or excludes tropical-extratropical coupling, we find a reduction in tropical interannual variability (~40%) and decadal variability in the southeastern tropical Pacific region (~70%) in the absence of SEP. Conversely, the absence of NEP yields no significant impact on tropical interannual variability but markedly diminishes decadal variability in the central tropical Pacific region (~70%). A comparative analysis of climate models and observational data reveals that most CMIP6 models underestimation the  extratropical Pacific's contribution, especially from the SEP, to the tropical Pacific climate dynamics.