UPDATE: President Barack Obama
welcomed Chancellor Angela Merkel to the White House on Friday for discussions on the escalating crisis in Ukraine
, her first visit to Washington since revelations that the US may have tapped her mobile phone.
Negotiations on a major transatlantic trade accord known as TTIP are also on the weighty agenda during Merkel's two-day visit that begins Thursday, accompanied by a joint press conference, the White House said.
Obama said in an interview broadcast in Germany in January that Merkel had no need to worry about the United States spying on her in future. But after Obama extended the invitation for a visit, Merkel noted that it would take "more than one trip" to repair the damage.
Her spokesman Steffen Seibert has said that, although Berlin last year pressed for a mutual "no-spy" pact with Washington, "concrete results" were not expected during Merkel's brief stay.
The US never seemed willing to sign on to such an agreement, observers say, while Obama stressed that his country would continue to conduct intelligence operations.
'Great deal of collaboration'
Earlier this week, Washington unveiled a raft of new sanctions against seven more individuals with close ties to Russian President Vladimir Putin and 17 companies mostly controlled by some of his powerful allies over Moscow's actions in neighboring Ukraine
Meanwhile, the EU added 15 Russians and Ukrainians to its Ukraine crisis sanctions list.
While warning Putin that steps could be taken to levy sanctions targeting the Russian economy - rather than individuals or particular businesses - the United States has so far refrained from acting on the option.
Transatlantic relations experts have noted that caution is being exercised due in large part to the reticence of certain European countries, particularly Germany, hoping not to expose themselves to reciprocal measures from Moscow.
Europe has maintained much tighter economic ties with Russia than the United States and would have more to lose from a cycle of retaliatory actions.
On Thursday, White House spokesman Jay Carney denied Washington and the EU had butted heads over possible new sanctions.
"There has been a great deal of collaboration and cooperation in that effort between the United States and the EU, as well as all the members of the G7, so we expect that effort to continue," he said.
"We expect to continue a path that sees an international coalition escalating the costs that Russia will have to endure and pay if Russia refuses to keep its commitments."
Carney added that the United States and EU members each have "a different kind of economic relationship with Russia, and so sanctions will affect different nations differently." 'Failure of leadership'
Some US lawmakers have expressed dismay at what they say is Merkel's interference in progress on the Russia question.
"I would tell her that I am not surprised but embarrassed at their failure of leadership. They're the leaders, they're being governed by the industrial complex from Germany," said hawkish Republican Senator John McCain, who is also meeting the German chancellor during her visit.
Republican Senator Jeff Sessions said that there needed to be "a clearer, more focused, more unified position, and Germany is right there in the middle of it."
Building US-European consensus on the TTIP should be easier, with both parties hoping to see the measure succeed next year. Merkel has enthusiastically supported the treaty in seeking opportunities for German companies.
During her trip to Washington, Merkel will also address the US Chamber of Commerce, and meet International Monetary Fund chief Christine Lagarde, and US senators.