Weeks after an openly transgender teenager from Southern California won a state title at the high school California Interscholastic Federation track-and-field finals, the Trump administration has concluded that the state allowing her to compete is a "clear violation" of Title IX.

In a , the U.S. Department of Education said that an investigation determined that two entities, the California Department of Education and the CIF, prevented "quality of opportunity" for female athletes by allowing competitors to participate in groups based on their gender identity. The CIF is the  that governs the highest level of high school sports in the state.

"The Trump Administration will relentlessly enforce Title IX protections for women and girls, and our findings today make clear that California has failed to adhere to its obligations under federal law," said U.S. Secretary of Education Linda McMahon. "The state must swiftly come into compliance with Title IX or face the consequences that follow."

What led to the investigation?

Last month, Mr. Trump opposed California's policy allowing transgender athletes to compete in high school sports. He called the circumstances "unfair" and "totally demeaning" to female athletes.

The president threatened to withhold federal funding from California if the transgender athlete, Jurupa Valley High School junior AB Hernandez, was allowed to compete at the state track and field championships. She ultimately was, and she won a state title in both the high jump and triple jump, and took second in the long jump.

Ahead of the state championships, the CIF revised its rules to ensure that athletes competing in the same division as Hernandez would retain the placements they would have earned if she had not participated. This resulted in "co-winners" for the high and triple jumps, with two cisgendered athletes sharing the top spot with Hernandez.

The CIF said it would adhere to a 2013 state law that aims to prevent sex-based discrimination at California schools.

was signed by then-Governor Jerry Brown and permits students to participate in "sex-segregated" activities, like sports, "consistent with his or her gender identity, irrespective of the gender listed on the pupil's records."

Last month, the Trump administration announced it would investigate whether AB 1266 violates Title IX requirements, which they determined it did on Wednesday.

What's next?

Now, the U.S. Department of Education says both the CIF and the California Department of Education have 10 days to agree to its proposed Resolution Agreement. 

The proposed agreement includes the following actions:

• All schools that receive federal funding must "comply with Title IX," which it says "forbids schools" from allowing transgender girls to compete in girls' sports or occupy girls' locker rooms. They must also adopt "biology-based definitions of the words 'male' and 'female'."
• Federal funding recipients must be notified by the California Department of Education that federal law overrules state law when it comes to Title IX 
• The CIF must retroactively restore individual records, championships and awards to cisgender athletes, if they were previously set or won by transgender athletes. The California Department of Education must also send personalized letters to those who have accomplishments restored "apologizing on behalf of the state of California for allowing her educational experience to be marred by sex discrimination." It's not clear how many athletes this would account for

If the California Department of Education or the CIF fail to reach an agreement on those terms within 10 days, the Trump administration says it could begin "imminent enforcement action" which includes referring the case to the Department of Justice for the next steps.

When asked for a statement and whether it planned to agree to comply, the CIF told CBS News Los Angeles that it "does not comment on legal matters."

Meanwhile, Gov. Gavin Newsom's office slammed U.S. Department of Education Secretary Linda McMahon, that she's "confusing government with her Wrestlemania days - dramatic, fake, and completely divorced from reality" and adding "this won't stick."