China is now the main energy importer from Central Asia, having secured large supplies of Turkmen gas and Kazakh oil. Beijing began to seek a role in the regional energy sector in the 2000s and consolidated this role further in the 2010s, with the construction of infrastructure channelling oil and gas eastwards. China is the main trading partner of Uzbekistan, Turkmenistan, and Kyrgyzstan. The European Union (EU) is Kazakhstan's main trading partner and the largest commercial actor in the region overall. Oil imports from Kazakhstan constitute the bulk of the EU's economic relationship with Central Asia. During the Soviet period, Central Asia provided a range of primary resources to the Union of Socialist Soviet Republics (USSR). The Kazakh, Turkmen, and Uzbek economies rely heavily on the fossil fuel sector and the extraction of other mineral or primary resources.