German Chancellor Olaf Scholz is flying to Washington this week on a mission to reassure Americans that his country stands alongside the United States and other NATO partners in opposing any Russian aggression against Ukraine.

Mr Scholz has said that Moscow would pay a “high price” in the event of an attack, but his government’s refusal to supply lethal weapons to Ukraine, bolster its troop presence in eastern Europe or spell out which sanctions it would support against Russia has drawn criticism abroad and at home.

“The Germans are right now missing in action. They are doing far less than they need to do,” Senator Richard Blumenthal, a Democrat and member of the Armed Services Committee, recently told an audience of Ukrainian Americans in his state of Connecticut.

This sentiment was echoed by Republican Senator Rob Portman, who questioned why Berlin had not yet approved a request to let NATO member Estonia pass over old German howitzers to Ukraine.

“That makes no sense to me, and I’ve made that very clear in conversations with the Germans and others,” Mr Portman told NBC.

Publicly, German officials insist their country is playing its part. Germany’s ambassador in Washington, Emily Haber, appeared on Fox News last month to defend Berlin’s restrictive stance on arms exports and highlight the generous economic support provided to Ukraine.

Yet in a confidential diplomatic cable beginning “Berlin, we have a problem,” Ms Haber warned that Germany risks being portrayed as an unreliable partner in Washington, Der Spiegel reported.

Much criticism has also focused on Germany’s heavy reliance on Russian supplies of natural gas and the construction of the Nord Stream 2 pipeline bringing that gas to Germany under the Baltic Sea, bypassing Ukraine.

The project has long been opposed by the United States but is strongly supported by Mr Scholz’s centre-left Social Democratic Party, most prominently its last chancellor, Gerhard Schroeder.

Mr Schroeder is close to Russian President Vladimir Putin and already heads the shareholders’ committee of Nord Stream AG and the board of directors of Nord Stream 2.

In a move likely to embarrass Mr Scholz ahead of his first trip to Washington, the Russian state-owned gas company Gazprom announced on Friday that Mr Schroeder — who has accused Ukraine of “sabre-rattling” in its standoff with Russia — has been nominated to join its board of directors.

Mr Scholz will meet President Joe Biden and members of Congress on Monday. The softly-spoken 63-year-old’s performance in Washington could have broad implications for US-German relations and Mr Scholz’s standing at home.

While former President Donald Trump frequently slammed Germany, accusing it of not pulling its weight internationally, his successor has sought to rebuild relations with Berlin.

Having succeeded long-time German leader Angela Merkel last year, Mr Scholz also needs to appease doubters at home who accuse him of pulling a diplomatic vanishing act compared to his European counterparts.

With the phrase “Where is Scholz?” trending on social media last week, German conservative opposition leader Friedrich Merz called for “clear words” from the government on the Ukraine crisis.