Steffen Seibert said Merkel had expressed her concerns to Trump during a telephone call on Saturday and reminded him that the Geneva Conventions require the international community to take in war refugees on humanitarian grounds.
"She is convinced that even the necessary, decisive battle against terrorism does not justify putting people of a specific background or faith under general suspicion," he said.
Seibert said the German government regrets the U.S. entry travel ban, would review the consequences for German citizens with dual nationalities, and would "represent their interests, if needed, vis a vis our U.S. partners".
Trump ordered on Friday a four-month hold on allowing refugees into the United States and temporarily banned travellers from Syria and six other mainly Muslim countries.
Seibert's comments were the first indication of discord over the issue between Merkel and Trump, who had highlighted common interests such as strengthening NATO and combating Islamist militancy in a joint statement after their 45-minute phone call.
Thomas Oppermann, who heads the parliamentary faction of the Social Democrats, the junior partner in Merkel's right-centre coalition, called Trump's order "inhumane and foolhardy" and said it would result in significant damage to the U.S. economy.
"The order contradicts everything that makes up the United States' good reputation as a country of immigration," he told Die Welt newspaper. "No one should be discriminated against because of their religious beliefs."
"The German government must stand up for the over 100,000 German citizens who are affected by the order," Nouripour told Reuters. He said Trump had not included Saudi Arabia in the order because of his strong business ties there.
Niema Movassat, a Left party lawmaker who also has German and Iranian citizenship, told the Tageszeitung newspaper that the ban would prevent him from visiting the United Nations to work on development issues and from visiting his relatives.
Dieter Janecek, economic spokesman for the Greens in parliament, said Germany should consider a travel ban on Trump and his senior adviser Stephen Bannon unless the order was rescinded.
Trump on Saturday accepted Merkel's invitation to attend the a meeting of the Group of 20 industrialised nations in Hamburg in July. He also invited Merkel to visit Washington soon.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)
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