China’s leading telecommunications firms Huawei and ZTE have secured a series of contracts this year to supply 5G equipment in Vietnam, in another sign of Hanoi’s warming ties with Beijing — a trend that has stirred concern among Western officials, Reuters reported, citing seven people with direct knowledge of the matter.

For years, Vietnam was viewed as hesitant to adopt Chinese technology in sensitive infrastructure. But in recent months, it has moved to embrace Chinese tech suppliers as previously strained relations with its northern neighbour have improved, while ties with Washington have cooled amid U.S. tariff actions targeting Vietnamese goods.

Although Sweden’s Ericsson and Finland’s Nokia have won contracts to build out Vietnam’s 5G core infrastructure, with U.S. chipmaker Qualcomm supplying network equipment, Chinese firms have begun to clinch smaller tenders with state-owned operators, according to public procurement data that has not been previously reported.