This study examines the relationship between the Northeast Asian and U.S. markets with particular attention placed on the global financial crisis period. For this purpose, the paper employs dynamic approaches including DCC-MGARCH, BEKK and Risk Decomposition models to ensure the robustness of empirical findings. The results are as follows. First, The Northeast Asian stock market remains relatively independent from the U.S. market movements during the sample period. Second, the regional market shows an increasing trend of joint integration with the U.S. market. Third, an increased integration is found to be only unique to the crisis period. We find no evidence to support the findings of previous empirical studies which suggest the increased level of integration since the GFC.