By Patricia Zengerle

WASHINGTON (Reuters) - The Republican chairman of the U.S. Senate intelligence committee called on Wednesday for American spy agencies to "pause" intelligence sharing with Germany's domestic intelligence agency that could be used to target the far right Alternative for Germany party (AfD).

"I understand that liberal elites on both sides of the Atlantic loathe the AfD, but AfD's platform has resonated with many Germans," Senator Tom Cotton of Arkansas wrote in a letter to Tulsi Gabbard, President Donald Trump's director of National Intelligence.

Germany's domestic intelligence service classified the AfD on May 2 as an "extremist" group, enabling it to step up monitoring of the country's biggest opposition party. The AfD declared the move a "blow against democracy" and has filed suit.

Cotton's letter follows a series of expressions of support for the AfD from members of Trump's circle. In it he asked that, until Germany's government "treats the AfD as a legitimate opposition party," Gabbard pause sharing of intelligence that could be used to target the party and refuse requests of assistance from German intelligence that could be used to surveil the AfD.

Cotton also asked for a review of whether U.S. intelligence under former President Joe Biden, a Democrat, cooperated with German requests to surveil the AfD or other opposition parties, and notify the Senate of the findings of that review.

Gabbard's office did not immediately respond to a request for comment. The German embassy in Washington also did not immediately respond. The new German chancellor, Friedrich Merz, a conservative, has warned the U.S. to stay out of his country's politics.

Members of Trump's inner circle have voiced support for the AfD. Secretary of State Marco Rubio, who is now also Trump's national security adviser, said Germany should reverse course on branding the AfD as "extremist."

Vice President JD Vance attacked German bureaucrats for "trying to destroy" the AfD. And close Trump ally billionaire Elon Musk threw his support behind the AfD before Germany's elections and warned against banning it.

(Reporting by Patricia Zengerle; Editing by Alexandra Hudson)