BERLIN — The U.S. refused to show any leniency to fugitive leaker Edward Snowden on Friday, even as Secretary of State John Kerry conceded that eavesdropping on allies had happened on “automatic pilot” and went too far.

Snowden made his appeal for U.S. clemency in a letter released Friday by a German lawmaker who met with him in Moscow. In it, the 30-year-old American asked for international help to persuade the U.S. to drop spying charges against him and said he would like to testify before the U.S. Congress about the National Security Agency’s surveillance activities.

Snowden also indicated he would be willing to help German officials investigate alleged U.S. spying in Germany, said Hans-Christian Stroebele, a lawmaker with the opposition Green Party and a member of the parliamentary committee that oversees German intelligence.

Stroebele met with Snowden for three hours Thursday, a week after explosive allegations that the NSA had monitored Chancellor Angela Merkel’s cellphone prompted her to complain personally to President Barack Obama. The alleged spying has produced the most serious diplomatic tensions between the two allies since Germany opposed the U.S.-led invasion of Iraq in 2003.

In his one-page typed letter, written in English and bearing signatures that Stroebele said were his own and Snowden’s, the American complained that the U.S. government “continues to treat dissent as defection, and seeks to criminalize political speech with felony charges that provide no defense.”

“However, speaking the truth is not a crime,” Snowden wrote. “I am confident that with the support of the international community, the government of the United States will abandon this harmful behavior.”

In Washington, State Department spokeswoman Jen Psaki would not respond directly to Snowden’s appeal but said the U.S. position “has not changed.”

“Despite recent reports or recent pronouncements from Mr. Snowden, as we’ve stated many times before, he’s accused of leaking classified information, faces felony charges here in the United States, and we believe he should be returned as soon as possible, where he will be accorded full due process and protections applicable under U.S. law,” Psaki said.

Stroebele said Snowden appeared healthy and cheerful during their meeting at an undisclosed location in Moscow. The German television network ARD, which accompanied Stroebele, said the Germans were taken to the meeting by unidentified security officials under “strict secrecy.”

Snowden “said that he would like most to lay the facts on the table before a committee of the U.S. Congress and explain them,” Stroebele said. The lawmaker, a prominent critic of the NSA’s alleged activities, said Snowden “did not present himself to me as anti-American or anything like that — quite the contrary.”

Merkel this week sent German officials to Washington for talks on the spying issue. Germany’s parliament also is expected to discuss the NSA’s alleged spying on Nov. 18.

Snowden’s appeal came as Kerry conceded that because of modern technology, some NSA activities had gone too far and were carried out without the knowledge of Obama administration officials.

“The president and I have learned of some things that have been happening, in many ways on an automatic pilot, because the technology is there,” Kerry said Thursday, speaking in a video link to an open government conference in London.

“In some cases, some of these actions have reached too far, and we are going to try to make sure it doesn’t happen in the future,” Kerry said, adding that ongoing reviews of U.S. surveillance will ensure that technology is not being abused.

Snowden was granted a one-year asylum in Russia in August after being stuck at a Moscow airport for more than a month following his arrival from Hong Kong. Russian President Vladimir Putin has said Snowden got asylum on condition that he wouldn’t harm U.S. interests.

Snowden’s exact whereabouts in Russia and his activities there have been a mystery, though there has been wide speculation that he is under the control of Russia’s security services.

Stroebele was tightlipped about where he met Snowden. The German politician said he had no contact with the German Embassy in Moscow nor with Russian authorities other than a passport control officer.

Snowden’s attorney says his client has accepted a technical-support job with a major Russian website but refused to name it.

“He enjoys living in Russia,” said lawyer Anatoly Kucherena.

He said Snowden is studying Russian and has developed some competency in it.

The Russian news site Life News on Thursday published a photo of Snowden on a boat in the Moscow River with the Christ the Savior Cathedral in the background. It said the photo was taken in September.