The ceremony, starting at 11.00 CET (14:00 Yerevan Time) on Saturday, will be attended by the presidents of European Union institutions, former and current heads of state and government and other dignitaries.
The ceremony was proposed by European Commission President Jean-Claude Juncker, who was nicknamed "Junior" by Mr Kohl and who described him as a mentor and friend.
World leaders past and present attended the military service before the coffin was put into a hearse and driven through the streets of Speyer to the cemetery where Kohl was laid to rest.
Chancellor Angela Merkel, who served as a minister under Kohl in the 1990s but later had a falling out over his role in receiving $1 million in illegal campaign cash donations, remembered Kohl as an at-times controversial figure with numerous enemies.
During his 16-year term as Germany's leader from 1982 to 1998, Kohl spearheaded his country's reunification in 1990 and was an architect of the continent's common currency, the euro.
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He added: "Helmut Kohl was a German patriot, but he was also a European patriot".
Speakers at the ceremony include the current German and French leaders Angela Merkel and Emmanuel Macron, respectively, as well as Russian Prime Minister Dmitry Medvedev, former U.S. President Bill Clinton, and former Spanish President Felipe González. East Germany's collapse paved the way to power for Merkel, an East Berlin physicist who joined the Christian Democrats and was recruited by Kohl for his post-unity cabinet.
Thank you for the opportunities you gave me.
EU Parliament President Antonio Tajani said Kohl deserved "a place of honor in the European pantheon" for unhesitatingly extending the hand of friendship to fledgling democracies in Eastern Europe following the fall of the Iron Curtain.
Following Saturday's ceremony in Strasbourg, Kohl's coffin was transported by helicopter to Germany and then taken down the Rhine river to Speyer, with thousands of people lining the roads and riverbanks to bid their farewell.
Dignitaries have been paying respects at his coffin, which has been draped in the European Union flag.
He was buried in a private ceremony at a cemetery in the city.