When asked about Obama's recent comments that he would press European NATO partners for more troops for Afghanistan, Merkel said Germany had no plans to go beyond pledges made last month for the NATO-led ISAF mission.
"I can give Barack Obama the good news that we will be boosting the mandate to include 1,000 more troops for the ISAF mission. We also just took over the command of the quick reaction force (in northern Afghanistan)," she said. "Thus I will make clear that we are not shirking our responsibilities for engagement but I will also make the limits very clear, just as I have done with the current president."
She said developments on the ground would require fresh assessments periodically.
"I will also say to Herr Obama that there has to be a balance between military engagement but also political expectations of the Afghan government" including the training of the Afghan security forces, she said.
Germany has faced growing pressure to bolster its presence in Afghanistan and redeploy troops from the relatively calm north of the country to the south where US-led forces are battling tenacious Taliban insurgents. In response to the calls, Berlin announced plans last month to boost its contingent in northern Afghanistan later this year by up to 1,000 soldiers to 4,500 troops.
But the mission is highly unpopular in Germany and any move to expand the deployment further would likely provoke a voter backlash. Obama is due to hold a major transatlantic speech at an open-air rally in the heart of Berlin in the early evening after talks with Merkel and Foreign Minister Frank-Walter Steinmeier.
Supporters estimate up to 500,000 people could attend the event but Berlin authorities say they expect a small crowd "in the tens of thousands range."
The Illinois senator is wildly popular here. A recent poll showed that 72 percent of Germans would cast a ballot for Obama if they could vote in the US presidential election, versus just 11 percent for his Republican opponent John McCain.