"What now worries all of us, the very serious situation in eastern Ukraine, will be a central focus, as well as how to react to it," said Merkel's spokesman Steffen Seibert, also citing transatlantic economic and trade issues.
Merkel is set to arrive Thursday and meet Obama Friday at the White House, where they will give a joint press conference before having lunch together.
Merkel will also address the US Chamber of Commerce, focssing on a planned trans-Atlantic free trade pact, and meet IMF chief Christine Lagarde and US senators.
Berlin-Washington ties were hit last year by revelations from fugitive intelligence contractor Edward Snowden of widespread overseas surveillance by the US National Security Agency, including of Merkel's mobile phone.
Seibert said that -- although Berlin last year pressed for a pact with Washington to commit both sides not to spy on each other -- "concrete results" are not expected during Merkel's visit.
Obama in 2011 honoured Merkel with a White House state dinner, and she repaid his hospitality by welcoming him last year to Berlin for a long awaited visit, when he delivered a speech before the Brandenburg Gate.
The US president in January invited Merkel back to Washington, hoping to mend fences after the row over US eavesdropping.
Washington never confirmed the eavesdropping, but it implicitly gave credence to the reports by the careful formulation of its response to questions from reporters.