Soon after Donald Trump took office, people with ties to the Chinese state poured hundreds of thousands of dollars into his re-election bid to get close to and potentially influence the new president.

The effort had early success in gaining access for those involved, helping them meet the president or top Republicans at fundraisers or at an internal GOP leadership meeting. It reveals how China seeks to build inroads into U.S. politics, gather information on U.S. leaders and if possible affect policy-making.

Several of those involved worked closely with China’s national-security apparatus, including organizations linked to its military, and briefed prominent Chinese political figures about their efforts…

There is no indication Mr. Trump was aware of the political contributions. The White House didn’t respond to requests for comment.