In a statement the ministry said:
"Latvia expresses outrage at Russia’s decision to deny MEP Sandra Kalniete’s entry into Russia."
"This step by Russia is certainly difficult to understand since it flies in the face of basic principles of humanity."
"Russia’s behavior in this case does not promote mutual respect and trust and has an impact on the atmosphere conducive to bilateral cooperation."
As Kalniete was also representing the European Peoples Party group in the European Parliament at the funeral, it also expressed its concern in a posting on the group's official website.
"This is already the third time that a Member of the European Parliament was stopped at the Russian border. The EPP Group calls on European Parliament President Martin Schulz to take necessary action and urgently address this issue with Russian authorities in order to allow MEPs to execute their duties," the group said.
EPP Group leader Joseph Daul said Rusia's actions were "unacceptable".
On Tuesday morning, after spending all night in a chair in the transit zone at Sheremetovo Airport in Moscow, Kalniete finally had her diplomatic passport returned to her - but not before being presented with a form telling her any future attempt to enter Russia would be a criminal offense.
Nice notice served to me by Russian border guards instead of my passport. Was warned: trying entering RU = criminal pic.twitter.com/utlFsp7Xdh— Sandra Kalniete (@Kalniete) March 2, 2015
Latvia will be represented at the funeral by Zanda Kalniņa-Lukaševica, parliamentary secretary to the Foreign Ministry.