"Today, the delegates did not discuss Ukraine or Crimea and sanctions will not be approved today," the diplomat said.
He added that the European Union is still planning to bring the issue up later in the week, saying: "This is our goal but there are some technical moments."
According to RIA Novosti's diplomatic sources close to the matter, the 28-member state bloc intended to approve the sanctions ahead of the European Council's meeting, which is to take place from December 18 to 19 in Brussels, Belgium.
The source said the bloc was united in its decision to impose more sanctions on the former Ukrainian republic, which voted to join Russia in a referendum in March. But he added, there were "preparations" to be completed ahead of the vote.
These moves follow the European Union's agreement in July to curb investment into certain sectors of the Crimean economy, and its ban of goods exported from the Crimean peninsula without Ukraine's permission.