Iran's Supreme Leader Ayatollah Ali Khamenei has accused Saudi Arabia of crimes in Yemen and said the war in Yemen would not be in Saudi Arabia's interests at the end of the day.

"The Al-Saud are committing crimes in Yemen, the United States is a partner in these crimes, and the crimes committed are aimed at Saudi Arabia's colonization of Yemen and control of its decision-making," Khamenei said in a speech on Wednesday. "The Al-Saud family should understand that the war in the end will not be in their favor."

"For four years they have been committing crimes in Yemen and targeting the oppressed people of Yemen, and they believed that they would control them in days or weeks, and the more they continue this war, the more they will be dealt with," he said.

Khamenei's speech came at a time when the parties to the Yemeni crisis were engaged in consultations in Sweden under the auspices of the United Nations. The Iranian Foreign Ministry welcomed the preliminary understandings that resulted from these consultations.

In his speech, Khamenei urged Iranians to maintain their unity, saying the United States would exploit divisions and likely to plot conspiracies against Iran in 2019.

"My advice to the Iranian nation, especially to the youth and the various institutions in the country, whether professional or political, is to be cautious and not to make it easier for the enemy," he said.