Several Democratic contenders for the 2020 US presidential election have named China as the biggest geopolitical threat to the United States, amid ongoing strategic clashes between Washington and Beijing over trade and technology. The first of the primary debates for a packed field of Democrats in Miami on Wednesday featured 10 of the 20 candidates and focused largely on domestic issues, but also touched on US foreign policy challenges. When debate moderators from broadcaster NBC asked candidates what they considered the greatest geopolitical threat to the US, four of the contenders named China: John Delaney, former congressman in Maryland; Minnesota Senator Amy Klobuchar; Julian Castro, the former secretary of housing and urban development; and Tim Ryan, congressional representative from Ohio. Delaney kicked off the answers by arguing: “The biggest geopolitical challenge is China, but the biggest geopolitical threat remains nuclear weapons.” Klobuchar said there were two threats: “Economic threat: China. But our major threat right now is what’s going on in the Middle East with Iran.” Ryan said that China was “without a question” the largest threat to the United States. “They’re wiping us around the world, economically,” he said, after telling a story earlier in the debate about US factory operations in Ohio moving to China. Castro kept his answer short and sweet: “China and climate change.” Several others, including Massachusetts Senator Elizabeth Warren – the highest-polling candidate on the stage – named climate change as the biggest threat. The references to the world’s second largest economy came as US President Donald Trump set off for the Group of 20 summit in Osaka, Japan, where he will hold a meeting with Chinese President Xi Jinping. China and the US have been embroiled in a year-long trade war and have tussled on the technology front, with Washington blacklisting Chinese telecoms company Huawei on national security grounds. Analysts have said that foreign policy will not play a major role in the US primaries, with voters focused more on matters closer to home, but the trade conflict with China will be an issue as the presidential election approaches next year. Many voices in Washington have also grown increasingly hawkish on China, with Democrats agreeing for the most part with the Republican Trump that there are inequities on trade, but disagreeing with the tactics the president has used, including unilateral tariffs and threats. Trump has blamed China for causing US job losses and claimed it has taken advantage of the United States for years on trade. The former real estate mogul has also suggested that China was hoping that a Democratic candidate would unseat him in 2020 and take a softer stance in their trade dispute. The second round of primary debates on Thursday will feature other major candidates, including former vice-president Joe Biden, who has said that China is “not competition” for the US, and Vermont Senator Bernie Sanders, who tweeted in May that it was “wrong to pretend that China isn’t one of our major economic competitors”.