U.S. Defense Secretary Ash Carter will visit Europe this week to urge NATO allies to adapt to a new kind of threat from Russia in the east and Islamic State to the south.
He is to meet with officials in Germany, Estonia and Belgium to encourage allied ministers to better work together in countering threats facing Europe.
U.S. officials say he will urge NATO to "dispose of the Cold War playbook" following the Kremlin's annexation of Crimea and its military support for Ukrainian separatists.
At a NATO meeting, defense ministers will discuss plans to increase alliance involvement in the fight against Islamic State militants in Iraq.
NATO leaders are expected to consider providing ministry-level advice and other training assistance in Iraq.
Carter also intends to discuss a U.S. proposal to send enough tanks, Humvees and other military equipment to outfit one brigade for exercises and other training programs in Eastern Europe. Carter has not officially approved the idea and officials have not said where the equipment would go, but there are indications Poland, which borders Russia, might be one location.
Poland Defense Minister Tomasz Siemoniak says he has had talks with Carter about putting the equipment in Poland and in four other eastern NATO nations.
Two weeks ago American and European defense and diplomatic leaders met with Carter and concluded the United States needs to strengthen its military exercises and training with nations in the region and bolster NATO's intelligence-sharing to better counter Russia.
The talks are sure to draw the ire of Russian President Vladimir Putin, whose economy is hurting due to low oil prices and U.S. and European Union sanctions against Russia for its actions in Ukraine.
At an investment conference Friday in Russia, Putin blamed the United States and European Union for triggering the Ukrainian crisis by refusing to take into account what he described as Russia's legitimate interests.
"They have pushed us back to the line beyond which we can not retreat,'' he said. "Russia is not seeking hegemony or some ephemeral superpower status.''
In Estonia, Carter will board the amphibious landing dock ship the USS San Antonio, which just finished leading the largest-ever multi-national Baltic Sea exercises. The annual operation involved 49 warships and 60 aircraft from 11 nations and more than 5,000 personnel.
During the exercises, which finished this week, Russian planes aggressively buzzed the U.S. and coalition ships and aircraft multiple times. Russia was a participant in the exercises until 2013.