Illhan Abdullahi Omar (Photo: Facebook)

WASHINGTON: Illhan Abdullahi Omar , one of the first two Muslim women in the US Congress, has "unequivocally" apologised for her remarks which sparked an anti-Semitism row and drew condemnation including from President Donald Trump who termed it a "terrible statement".

Omar, a Democrat who was elected to the House of Representatives in November, in a tweet on Sunday questioned the financial relationship between the powerful American Israel Public Affairs Committee (AIPAC) and members of the Congress.

While reacting to a Republican critic, Omar, 37, said, "It's all about the Benjamins baby," referring to American USD 100 bills featuring the likeness of Benjamin Franklin.

"Anti-Semitism is real, and I am grateful for Jewish allies and colleagues who are educating me on the painful history of anti-Semitic tropes," Omar, the first Somalian American lawmaker, said on Monday.

"My intention is never to offend my constituents or Jewish Americans as a whole. We have to always be willing to step back and think through criticism, just as I expect people to hear me when others attack me for my identity. This is why I unequivocally apologise," she said, after top Democratic leaders sought an apology from her on her tweets.

On Monday, Trump told reporters abroad Air Force One that the apology was not enough.

"I think she should be ashamed of herself. I think it was a terrible statement and I don't think her apology was adequate," he said.

Asked what she should say, Trump replied, "she knows what to say".

Democratic leaders led by House Speaker Nancy Pelosi described her tweets as highly offensive.

"We are and will always be strong supporters of Israel in Congress because we understand that our support is based on shared values and strategic interests. Legitimate criticism of Israel's policies is protected by the values of free speech and democratic debate that the United States and Israel share," they said.

"But Congresswoman Omar's use of anti-Semitic tropes and prejudicial accusations about Israel's supporters is deeply offensive. We condemn these remarks and we call upon Congresswoman Omar to immediately apologise for these hurtful comments," Democratic leaders said.

Congressman Dean Phillips had an impassioned, face to face conversation with Omar during which he expressed offense to her recent anti-Semitic tropes and extended an invitation for future discussions aimed at fostering a better understanding between Jewish and Muslim members of Congress.

"I strongly condemn anti-Semitism in all its forms, including comments made by my colleague that - purposefully or not - have propagated dangerous and destructive stereotypes of the Jewish people and the State of Israel.

"As elected leaders, it is our collective responsibility to set standards of respect and elevate understanding between the communities we represent," he said.

Omar and her Democratic colleague from Minnesota were the first two Muslim women elected to the House of Representatives during the last November mid-term polls.

"As Americans and Jews, we expect our politicians to condemn bigotry, not to fuel it. Words matter. At a time when anti-Semitism is on the rise in the US and abroad, Rep Omar is promoting the ugly, anti-Semitic conspiracy theory that Jews have an outsized influence over politics," said Jonathan A Greenblatt, CEO and national director of the Anti-Defamation League.

Omar was elected to the House of Representatives from Minnesota on a Democratic party ticket last November.

