Texas Central Partners has secured a $300 million loan to continue its pursuit of a new 240-mile high-speed rail route from downtown Dallas to Houston.

The company said it will use the financing to move ahead on permitting, design and engineering on what would be the first high-speed rail in America.

The loan is backed by Japanese sources, including the nation's only public-private fund that specializes in overseas infrastructure. Texas Central plans to use Japanese Shinkansen technology for its bullet train.

"This is a loan to be paid back with interest," the company said in a written statement Thursday. "It does not change the train's majority-Texan ownership."

When added to its current equity — much of which comes from its Texas investors — the loan will get the company to "the point at which all of the capital required to construct is fully committed" and construction is authorized, Texas Central officials said.

Texas Central officials said this month the project would cost $12 billion to $15 billion and would be privately funded. Others believe it could cost closer to $20 billion. Texas Central's proposal is to create a 90-minute trip between the two cities with a single stop in Grimes County near Texas A&M University.

The company hopes the train line could open as soon as 2024. But construction, which Texas Central believes would take about five years, couldn't begin until the company receives final environmental clearance.

During a series of hearings that ended last week, officials with the Texas Commission on Environmental Quality — one of the agencies tasked with studying the project — said it typically takes a year or longer to issue a permit, add conditions or deny a permit. TCEQ, which also has never studied a project like the bullet train, started its work in late 2017.

The Federal Railroad Administration, meanwhile, is looking to finalize its Environmental Impact Statement by Jan. 31. The administration issued a draft statement in December. It hopes to make a decision on the project, which would be based on the final report, by the end of August 2019.

The public comment period on the draft statement is closed. However, the administration offers answers to frequently asked questions on its website.