Archbishop Elpidophoros, head of the Greek Orthodox Church in the United States, received a phone call from former Vice President Joe Biden, who shared his solidarity with the effort to maintain Hagia Sophia’s current status as a museum.

Elpidophoros, who arrived from Turkey a little over a year ago to assume the role of Archbishop of America has become one of the most vocal and outspoken opponents to Turkish President Recep Tayyip Erdoğan’s decision convert the sacred site into a mosque.

In a Tweet, the Archbishop expressed his gratitude to the Democratic Presidential candidate for the phone call.

“I was grateful to receive a call from VP @JoeBiden, expressing his support of our Ecumenical Patriarchate, and his solidarity with our cause to maintain the status quo for #HagiaSophia,” Elpidophoros Tweeted from his official account.

The Archbishop has called on Greek Orthodox faithful in the United States to make their voices heard on the issue.

“We must arise and as the People of God, make our voices heard from Washington State to Washington, DC, and not lose heart, lose faith, or lose courage because, though our struggle may be long, it is not without our ultimate hope,” Elpidophoros said in an encyclical to all Greek Orthodox Christians in the United States.

“Therefore, let us arise – as Orthodox Christians, as people of conscience with a righteous cause. Let us make our presence and our voices known,” he said.

He also designated July 24– the first date of Muslim prayers set to take place in Hagia Sophia— a national day of mourning in the Archdiocese of America and called on churches to observe certain services, hymns and the rolling of bells of mourning.

Biden had previously made a public statement against Erdogan’s move to convert the historic Orthodox Church into a mosque.