Israel is blocking two United States Democratic lawmakers and prominent critics of Israel, Ilhan Omar and Rashida Tlaib, from visiting.
Ilhan Omar and Rashida Tlaib were due to visit the occupied West Bank and East Jerusalem next week.
Both have supported the boycott movement against Israel, but Israeli law allows supporters of the campaign to be banned from visiting.
President Donald Trump earlier tweeted it would show "great weakness" if the pair were allowed entry.
On Thursday, Mr Trump took to Twitter to urge that they be blocked from visiting, adding that "they hate Israel & all Jewish people, & there is nothing that can be said or done to change their minds".
The two US lawmakers have yet to comment on the decision.
Why have they been banned?
Israeli law blocks entrance visas to any foreigner who calls for any type of boycott that targets Israel - either economic, cultural or academic.
The law attempts to suppress the "boycott, divest, sanction" movement, which has drawn growing support across Europe and the US.
Israeli officials had earlier said they would make an exception for the elected US officials, before backtracking.
According to US media, their trip was meant to begin on Sunday, and would include a stop at one of the most sensitive sites in the region - a hilltop plateau in Jerusalem known to Jews as the Temple Mount and Muslims as Haram al-Sharif.
They also planned to visit Israeli and Palestinian peace activists and travel to Jerusalem and the West Bank cities of Bethlehem, Ramallah and Hebron.
The trip to the West Bank was planned by Miftah, an organisation headed by Palestinian peace negotiator Hanan Ashrawi.
Ms Tlaib was planning to stay for two extra days to visit her grandmother, who lives in a Palestinian village.
Critics of Trump
President Trump, who has a close relationship with Israeli Prime Minister Benjamin Netanyahu, has frequently feuded with the lawmakers and in remarks widely condemned as racist, told them to "go back" to the countries that their families were from.
Ms Tlaib, a Palestinian American, was born in Michigan, and Ms Omar is from Minnesota but was born in Somalia.
After the Democratic-led House of Representatives voted against the boycott against Israel movement in July, Ms Tlaib criticised the country as "racist".
"I can't stand by and watch this attack on our freedom of speech and the right to boycott the racist policies of the government and the state of Israel."
The House also voted to condemn hate speech in a move directed at Ms Omar for her criticism of US support for Israel.
"It's all about the Benjamins baby," Ms Omar had tweeted in a reference to the US $100 note, leading to allegations that she was using a negative stereotype for Jews.
She later apologised, and said the tweet was meant to criticise lobbyists, not Jews. She also thanked "Jewish allies and colleagues who are educating me on the painful history of anti-Semitic tropes".
What has Israel said?
A statement from the Israeli Interior Ministry confirming the ban said it was "inconceivable that those who wish to harm the state of Israel while visiting would be granted entry".
But only last month Israeli ambassador Ron Dermer said the two Democrats would be permitted to visit "out of respect for the US Congress and the great alliance between Israel and America".
On Wednesday, Mr Netanyahu held consultations with the country's foreign minister, interior minister, National Security Council chief and attorney general, according to Haaretz newspaper.
In a statement on Thursday, Mr Netanyahu said "there is no country in the world that respects the US and the American Congress more than Israel."
"However, the itinerary showed that the congresswomen's sole intention was to harm Israel."
What's the reaction?
The US ambassador to Israel said in a statement that the US "supports and respects the decision of the Government of Israel to deny entry".
Israel "has every right to protect its borders against those activists in the same manner as it would bar entrants with more conventional weapons," wrote Ambassador David Friedman.
The American Israel Public Affairs Committee (AIPAC), said in a tweet while they disagree with the lawmakers' support for the boycott movement against Israel, they also believe "every member of Congress should be able to visit and experience our democratic ally Israel firsthand".
New Jersey Congressman Tom Malinowski called the decision "disrespectful to Congress" and said during a cross-party congressional trip to Israel last week officials had assured them their colleagues would be allowed to visit.
"First he tells Congresswoman Tlaib to 'go back' to 'her' country, and then he tells that country not to let her in," he tweeted, referring to Mr Trump's comments.
Massachusetts Senator and presidential candidate Elizabeth Warren called the move "shameful" and "unprecedented" against a member of the US Congress.
Senator Bernie Sanders, a Democratic presidential candidate, said in a tweet "opposing Netanyahu's policies is not 'hating the Jewish people'".