The detained American basketball star is expected to be sent to a penal colony after a court upheld her 9-year-sentence, raising pressure on the U.S. to negotiate her release.

With the decision on Tuesday by a Russian appeals court to uphold Brittney Griner’s sentence on drug smuggling charges, the American basketball star’s best hope for freedom now likely depends on the outcome of delicate talks between the United States and Russia, two governments whose relations are at their lowest point in decades.

The Biden administration and President Vladimir V. Putin’s government have engaged in secretive negotiations about a possible exchange of prisoners, and back in June the Biden administration offered a swap involving Ms. Griner. But Kremlin officials have said repeatedly that it was premature to discuss a deal until the judicial process has run its course.

The ruling on Tuesday by a three-judge panel of an appeals court near Moscow means that Ms. Griner will soon begin serving a nine-year sentence at a prison colony. President Biden’s national security adviser, Jake Sullivan, denounced the ruling as “another sham judicial proceeding” and said that U.S. officials have “continued to engage with Russia through every available channel” to secure the freedom of Ms. Griner and other Americans they believe are wrongfully detained in Russia.

“The president has demonstrated that he is willing to go to extraordinary lengths and make tough decisions to bring Americans home,” Mr. Sullivan said.

One person briefed on the talks between Moscow and Washington this summer said that the United States had proposed exchanging Ms. Griner — along with Paul Whelan, a former Marine held since December 2018 — for Viktor Bout, a Russian arms dealer serving a 25-year federal prison sentence for charges including conspiring to kill Americans.

Mr. Biden and Mr. Putin are both expected to attend a summit of Group of 20 leaders next month in Indonesia, and Mr. Biden has said he would only speak with the Russian leader there if it was to discuss Ms. Griner’s case.

Bill Richardson, the former ambassador to the United Nations who has been unofficially negotiating with Russian officials as a private citizen, said in October that he was “cautiously optimistic” that Ms. Griner and Mr. Whelan could be exchanged before the end of the year.

Ms. Griner, 32, participated in the proceedings on Tuesday via a video link from the detention center where she has been held since her arrest on Feb. 17. It could be a few months before she is moved to a prison colony to serve her sentence, her lawyers said.

There are two higher courts above the appellate division, culminating in the Supreme Court, but Ms. Griner’s lawyers said they had not decided whether to take the case any further.

Higher courts in Russia are not known for overturning verdicts, especially in a case involving foreign policy and the interests of the Kremlin.

Since her arrest at a Moscow airport days before Russia invaded Ukraine, Ms. Griner’s fate has become entangled in the increasingly acrimonious relations between Moscow and Washington over the war. American officials have accused Russia of using Ms. Griner and other U.S. citizens in Russian custody as bargaining chips.

Ms. Griner, an all-star center with the WNBA’s Phoenix Mercury and a two-time Olympic gold medalist, was en route to Yekaterinburg, a city near the Ural Mountains, where she played for a women’s basketball team. Customs officials said they found two vape cartridges containing hashish oil in her luggage.

Ms. Griner admitted her guilt in court but said that she had no intention to break the law, maintaining that the small amount of hashish oil appeared in her luggage because of negligence.

Since she was sentenced in August, her lawyers have argued that the nine-year prison term — near the 10-year maximum for such a conviction — was too harsh for a first-time offense and was politically motivated.

“The verdict contains numerous defects, and we hoped that the court of appeal would take them into consideration,” her lawyers said in a statement after her appeal was denied.