The Biden administration has determined that WNBA star Brittney Griner is being wrongfully detained in Russia, meaning the United States will more aggressively work to secure her release even as the legal case against her plays out, the State Department said on Wednesday.

"The US government will continue to undertake efforts to provide appropriate support to Ms. Griner," the department said.

Griner was detained at an airport in February after Russian authorities said a search of her bag revealed vape cartridges containing oil derived from cannabis. Since then, US officials had stopped short of classifying the Phoenix Mercury player as wrongfully detained and said instead that their focus was on ensuring that she had access in jail to United States consular affairs officials.

Now, though, US officials have shifted supervision of her case to a State Department section — the Office of the Special Presidential Envoy for Hostage Affairs — that is focused on negotiating for the release of hostages and other US citizens classified as being wrongfully detained in other countries. A consular officer did visit in March.

"Brittney has been detained for 75 days and our expectation is that the White House do whatever is necessary to bring her home," said Griner's agent, Lindsay Kagawa Colas.

The president of the WNBA players' union, Nneka Ogwumike, noted in a separate statement that "it has been 75 days that our friend, teammate, sister, Brittney Griner, has been wrongfully detained in Russia."

"It is time for her to come home," Ogwumike added. "Having learned that the US government has now determined that BG is being wrongfully detained we are hopeful that their efforts will be significant, swift and successful."

It was unclear what prompted the shift in approach to Griner's case, though President Joe Biden's administration had been under pressure from members of Congress and others to make her release a priority.

The US last week secured the release of Marine veteran Trevor Reed as part of a prisoner swap that also resulted in a convicted Russian drug trafficker being freed from prison in the US.

ESPN first reported the classification in Griner's case.

Meanwhile, the WNBA announced Wednesday that it would honour Griner with a floor decal and allow the Mercury to pay her without it counting against the team's cap. The decal will feature Griner's initials, BG, as well as her No. 42.

All 12 teams will have the decal on their home courts starting with the season opener on Saturday night. The Mercury open their season at home that night against the Las Vegas Aces.