US Secretary of Defence Lloyd Austin will travel to Israel, Germany, Britain and the Nato headquarters in Belgium in the coming week for talks with government and military leaders. Mr Austin will become the highest-ranking official from President Joe Biden's administration to visit Israel, where he will meet Prime Minister Benjamin Netanyahu and Defence Minister Benny Gantz for talks on "shared priorities" and reaffirm Washington's commitment to Israel maintaining military superiority over its neighbours, according to a Pentagon statement. In Europe, he will hold talks with German defence minister Annegret Kramp-Karrenbauer and Chancellery Foreign and Security Policy Adviser Dr Jan Hecker, Nato Secretary General Jens Stoltenberg and British Defence Secretary Ben Wallace. Mr Austin will leave Washington on Saturday, but the dates for his stops in each country were not given. The trip coincides with rising tensions between Israel and Iran just as the Biden administration tries to engage Tehran over a return to the nuclear pact effectively torn up by former president Donald Trump. In Europe it comes as Russia sent shivers across the continent with the massing of troops and war equipment along its border with Ukraine. "Russia now has more troops on the border of Ukraine than at any time since 2014," White House press secretary Jen Psaki said on Thursday. Mr Biden was "increasingly concerned", she said.