U.S. Defense Secretary Lloyd Austin was due on April 10 to embark on a series of overseas meetings with U.S. allies amid rising tensions between Ukraine and Russia and what Washington calls Moscow’s “destabilizing behavior.”

During the week ahead, Austin is due to meet with government and military leaders in Israel, Germany, at NATO Headquarters in Belgium, and in the United Kingdom. .

A Pentagon statement late on April 8 said Austin will “meet with his counterparts and other senior officials to discuss the importance of international defense relationships, and reinforce the United States’ commitment to deterrence and defense, burden sharing, and enduring trans-Atlantic security.”

The Pentagon says Austin’s April 14 meeting in Brussels with NATO Secretary General Jens Stoltenberg will focus on “how the Alliance is tackling destabilizing behavior by Russia,” as well as “rising China, terrorism, and global challenges such as COVID-19 and climate change.”

Ahead of that meeting, Austin was scheduled to visit in Berlin with German Defense Minister Annegret Kramp-Karrenbauer and Chancellery Foreign and Security Policy Adviser Jan Hecker.

The Pentagon says the agenda of Austin’s Berlin talks include “combatting the malign influence of our shared strategic rivals, and continued dialogue on U.S. force posture in Germany and elsewhere.”

Austin’s tour starts a day after U.S. Secretary of State Antony Blinken consulted the German and French foreign ministers about the need for Russia to cease its military buildup in the occupied Crimean Peninsula and near Ukraine’s eastern borders.

Washington has accused Russia of “provocations” in eastern Ukraine and using “inflammatory rhetoric.”

A statement from the U.S. State Department said Blinken spoke separately with German Foreign Minister Heiko Maas and French Foreign Minister Jean-Yves Le Drian about the need for stepped-up consultations among NATO allies as fears grow of a major escalation in the eastern Ukraine conflict.

Kyiv and the West blame the Russia-backed separatists holding parts of the Donetsk and Luhansk regions for a recent spike in hostilities, while Moscow has pointed the finger at Kyiv.

A recent accumulation of photographs, video, and other data has revealed major movements of Russian armed forces toward or near Ukraine’s borders and into Ukraine’s Russian-occupied Crimean Peninsula.

That has fueled concerns that Moscow may be preparing to send forces into eastern Ukraine.

The Kremlin has rejected Western calls to pull back its troops, denying they are a threat while adding that military movements within Russia are an internal sovereign issue.

On April 9, the Kremlin issued a stark warning that Russia could take steps to “protect civilians” in the region in the event of a resumption of full-scale combat operations there.

The first stop on Austin’s four-country tour is Israel where he is to meet with Prime Minister Benjamin Netanyahu and Defense Minister Benjamin Gantz.

The final item on Austin’s agenda, after visiting NATO headquarters in Brussels, is talks in the United Kingdom with Secretary of State for Defense Ben Wallace.

The Pentagon says the purpose of that visit is “to reaffirm the continuing importance of U.S.-United Kingdom defense cooperation to meet global security challenges.”

With reporting by Reuters