Ukraine's highest court on Wednesday upheld the conviction of former Prime Minister Yulia Tymoshenko for abuse of office, a case that has strained the former Soviet state's ties with the West.

Tymoshenko was an architect of Ukraine's 2004 Orange Revolution that promoted democracy and unsuccessfully ran for president in 2010. She was sentenced to seven years in prison in October 2011, when she was found guilty of exceeding her powers while negotiating a gas contract with Russia while she was prime minister.

The contract significantly increased the price Ukraine pays for Russian gas imports that are critical to the country.

Her supporters say the trial is a politically motivated attempt by her rival, President Viktor Yanukovych, to keep her out of October elections. The government denies the accusations.

Russian President Vladimir Putin, Tymoshenko's counterpart in signing the gas deal, has said there was nothing illegal in her actions.

Judge Oleksandr Elfimov said the court had "found no grounds to uphold (Tymoshenko's) appeal" of the verdict, and that the prison term is "adequate to the gravity of the crime."

Several members of the audience yelled "Shame!" upon hearing the verdict.

Several Western nations have criticized the case against the ex-premier, along with the conviction and four-year prison sentence of Yuri Lutsenko, a former interior minister under Tymoshenko.

"Obviously, we are disappointed by the decision," U.S. State Department spokeswoman Victoria Nuland said Wednesday. "We continue to urge the government of Ukraine to free Mrs. Tymoshenko and other members of the government and to restore their full political and civil rights."

The court hearing was attended by former Polish President Aleksander Kwasniewski and former President of the European Parliament Patrick Cox.

"This and past court rulings have nothing to do with justice," Tymoshenko aide Oleksandr Turchinov said.

Lawyers for Tymoshenko are appealing the conviction in the European Court for Human Rights.

Tymoshenko's daughter Eugenia described the hearing as a "shameful decision, which proves one more time that a dictatorship has come to Ukraine."

Kiev-based political analyst Mykhailo Pogrebinsky said Wednesday's ruling "has brought Ukraine's legal system into a deadlock." ''Criminal prosecution for a political decision can hardly be called the rule of law," he said.

Tymoshenko retains a strong following in Ukraine. At least 500 supporters gathered Wednesday outside the courthouse in Kiev, chanting "Freedom to Yulia!"

After the hearing, Tymoshenko's supporters held a mock funeral procession, carrying a small coffin with a figure of Themis, the Greek goddess of justice, inside. They buried the coffin in the courthouse's yard and erected a cross with the plaque: "Ukraine's justice lies here."