President Vladimir Putin says Russia will do its utmost to stop the bloodshed in Ukraine, where government forces are fighting pro-Russian separatists in the east.
Putin was speaking at a meeting with Russian lawmakers in Crimea, which Russia annexed in March.
He said Ukraine "has sunk into bloody chaos, in a fratricidal conflict," and that the situation was deteriorating with each passing day.
He did not spell out how Russia intended to help end the conflict in eastern Ukraine.
He also said that Russia must not "fence itself off from the outside world" and should not break ties with partners. "But we should also not let them treat us with disdain," he said.
He said Russians needed to "consolidate and mobilize but not for war or any kind of confrontation." He said Russians must mobilize "for hard work in the name of Russia."
Western countries have imposed a raft of sanctions on Russia over its annexation of the Ukrainian peninsula of Crimea and its perceived support for the pro-Russian separatists in eastern Ukraine.
Russia denies it is supplying the separatists with weapons and expertise, and Moscow has banned the import of most meat and dairy products from the Western states imposing sanctions against Russia.
Putin told lawmakers at the meeting in Yalta that he was forced to announce the food ban to protect Russia's national interests and also help revive domestic agriculture.
He also said the measures would help Moscow's new allies in Latin America and countries such as Turkey play a bigger role on the Russian market.
Putin announced he had approved a Defense Ministry plan establishing a Russian military task force in Crimea but said the presence would not be "excessive or expensive."
The two-day visit to Crimea is Putin's second to the Black Sea peninsula since its annexation.
The presidential press service had touted Putin's address as a "major speech," and many had anticipated an announcement on Ukraine, but correspondents say Putin's comments were rather conciliatory in tone.
Ukraine has denounced the visit, but Putin dismissed Kyiv's protests, saying Crimea should become a symbol of a powerful and unified Russian state.