Taiwanese Foreign Minister Lin Chia-lung visited the US state of Arizona for the opening of a new de facto consulate in Phoenix, his office said on Sunday, Reuters reported. The United States is Taiwan’s most important international partner and arms supplier, despite the absence of formal diplomatic ties. Taiwan’s foreign ministry said the new office in Phoenix marks a milestone in the Taiwan-US economic and trade partnership. Taiwanese chipmaker TSMC is investing 265 billion dollars in Arizona to make semiconductors, Reuters reported. In a statement, the ministry said it would continue to link diplomacy, trade and economics, deepening the mutually beneficial partnership between Taiwan and the United States based on mutual trust. Lin’s visit followed stops in Belize and Guatemala. He was expected to tour TSMC’s Arizona plants and meet local officials, according to reports. While senior Taiwanese officials visit the US from time to time, President Lai Ching-te has yet to do so under the second Trump administration. The visit underlines how chips and trade have become the core of Taiwan’s unofficial diplomacy with Washington.