Kiev, Vilnius: Ukraine on Tuesday prepared to send a team of doctors to check the health of a hunger-striking helicopter pilot who is on trial in Russia as global calls grew for her release.

US Vice-President Joe Biden added his voice to concern expressed by the European Union (EU) on Monday about the fate of 34-year-old Nadiya Savchenko.

“Nadia has been unjustly imprisoned in Russia since 2014 — detained and facing trial on trumped up charges,” Biden said in a statement.

“Her unlawful continuing detention is a clear violation of Russia’s commitment under the Minsk agreements, and she should be freed at once,” he added in reference to a deal signed in the Belarussian capital aimed at ending Ukraine’s separatist war.

Meanwhile, five EU states have proposed sanctions against Russian officials responsible for the trial of Savchenko, Lithuanian Foreign Minister Linas Linkevicius said on Wednesday.

Savchenko is on trial for alleged involvement in the death of two Russian state television journalists in a mortar attack that occurred two months after Ukraine’s pro-Moscow eastern revolt broke out in April 2014.

The 34-year-old Iraq war veteran, who denies the charges, faces up to 23 years in prison if convicted in a case that has drawn global attention and inspired protests.

“Officials directly involved in this fabricated case must face consequences. We see that protests, letters and statements have failed to bring results,” Linkevicius said.

The initiative, cosigned by the foreign ministers of Britain, Poland, Romania and Sweden, will be presented to EU foreign policy chief Federica Mogherini this week.

The proposed “Savchenko list” would require the European Union to introduce visa restrictions and asset freezes on those “responsible for her illegal detention, incarceration and sentencing”, Linkevicius said.

Savchenko on Wednesday vowed to continue her hunger strike. She has refused all food and drink since her hearing was adjourned last Thursday before she was given a chance to make a final statement.

The verdict will be handed down on March 21 and 22, according to the judge.