Israeli Prime Minister Benjamin Netanyahu has reportedly threatened to cancel a meeting with German Foreign Minister Sigmar Gabriel on Tuesday (25 April) if the German politician did not withdraw from meetings with pro-rights groups.

Gabriel, who arrived in Israel on Monday, was due to meet with representatives from B'Tselem and Breaking the Silence in addition to his meeting with Netanyahu.

Senior sources within Netanyahu's office told Israel's Channel 2 news that an ultimatum to cancel the engagements was issued to Gabriel, however German diplomats have said the politician intended to go to all meetings as planned.

Gabriel is also scheduled to meet with President Reuven Rivlin and opposition chairman Isaac Herzog.

Herzog issued a statement on Monday condemning Netanyahu's alleged threats.

"Netanyahu's ultimatum to the German foreign minister is a serious blow to Israel's foreign relations with the biggest economy in Europe and a true friend of Israel," he said, reported Haaretz.

"Instead of running away from the campaign, I call on Netanyahu to meet with the German foreign minister and present his positions and Israel's positions, without fear of any organisations."

Rivlin did not publicly make any comments about Netanyahu's alleged threats, but at a Holocaust Remembrance Day ceremony in Jerusalem, he said that it was wrong to think that every criticism of Israel constitutes anti-Semitism – a stance often voiced by Netanyahu.

Groups such as B'Tselem and Breaking the Silence are occasionally labelled as anti-Semitic, but they have long maintained their work is for the long-term benefit of Israelis.

Rivlin said considering criticism of Israel as anti-Semitic was "fundamentally wrong", adding that it is dangerous for the people of Israel to automatically confuse political criticism with references to the Holocaust as it undermines the history of the genocide.