Fischer's three-day visit to Washington, which began on Monday, is a further sign of improving transatlantic ties, but it comes in the wake of the widening scandal over the alleged mistreatment of Iraqi prisoners by their American guards in the Abu Ghraib prison near Baghdad.
Speaking to reporters after talks with Powell, Fischer said the United States must restore its "moral leadership" of the world by carrying out a full investigation of the abuse scandal.
"We need the United States, we need the moral leadership of the United States, it is important for the West, for all of us," he said.
He said German was hoping that the various investigations and inquiries under way by American authorities would lead to the U.S. regaining its moral weight, which he said was "crucial for all us."
"Those who are responsible must be brought to justice," Fischer said.
As the scandal over the apparent systematic human rights abuses by U.S. forces in Iraqi prisons widens with the publication of new photographs of torture, anger has been growing in Germany at the perceived lapses of the American military as well as the Bush administration.
Fischer told reporters that Germany had been "really shocked and deeply appalled" by the pictures that have been released of the prisoner abuse.
Powell also spoke to reporters, saying he and Fischer exchanged views on "how deplorable the situation is for all of us." He said all Americans were shocked by the images just as people around the world were, adding: "We are going to get to the bottom of this and make sure that justice is done."
Besides meeting with Powell, Fischer will meet National Security Adviser Condoleezza Rice during his visit.
Schily: "Abuse, a serious blow"
German officials have been frank in their criticism of the prisoner abuse. Interior Minister Otto Schily and German Justice Minister Brigitte Zypries -- also currently in the U.S. capital -- minced no words in conveying their outrage at the torture scandal.
Schily told reporters the graphic photographs of American soldiers abusing naked Iraqi prisoners were "a serious setback in the battle against terrorism" because they dealt a serious blow to efforts to win hearts and minds in the Islamic world.
"Repairing the damage will pose serious difficulties," Schily said. "This matter must be dealt with, and a clear signal must be sent. I don't think one can simply say one is sorry and then go back to business as usual," Schily said.
Zypries urged the U.S. to sign up to the International Criminal Court and stressed that the abuse of human rights by occupation forces in Iraqi prisons demonstrated how important the battle is "for the globalization of basic rights."
However, Fischer is treading carefully during his visit, as it comes only two months after German Chancellor Gerhard Schröder was invited to the White House to mend ties with U.S. President George Bush. Schröder and Fischer strongly opposed the U.S.-led war in Iraq, angering Bush and cooling relations between Berlin and Washington.
Fischer will also likely discuss Rice's plans to come to Berlin in two weeks to meet with German and Russian officials. While in the German capital she will also hold talks with Palestinian Prime Minister Ahmed Qurei, which will be Washington's highest level contacts with the Palestinian Authority in almost a year. Whether Fischer will play a role is unclear, but he has been seen as an honest broker between Israel and the Palestinians in the past.
At the end of the week, Fischer will take part in preparatory talks in Washington for the upcoming G-8 summit in June. German Interior Minister Otto Schily and Justice Minister Brigitte Zypries will also attend the meeting to discuss international efforts in the war against terrorism.