Priti Patel has apologised for taking time out of a family holiday to meet Israeli prime minister Benjamin Netanyahu and other politicians without telling the Foreign Office in advance.
The international development secretary has also been reprimanded by Downing Street for her actions.
Labour said Patel must either be investigated by the Cabinet Office or resign.
Patel was accompanied to nearly all of her meetings with Israeli ministers, charities and non-governmental organisations by honorary president of the Conservative Friends of Israel lobbying group, Lord Polak.
She apologised for setting up and reporting the meetings “in a way which did not accord with the usual procedures” and clarified her claim that Foreign Secretary Boris Johnson “knew about the visit”, admitting he did not know about it in advance.
The BBC was the first to report on Friday that Patel had undisclosed meetings.
Patel said in a statement on Monday: “This summer I travelled to Israel, on a family holiday paid for myself.
“While away, I had the opportunity to meet a number of people and organisations. I am publishing a list of who I met. The Foreign and Commonwealth Office was aware of my visit while it was under way.
“In hindsight, I can see how my enthusiasm to engage in this way could be misread, and how meetings were set up and reported in a way which did not accord with the usual procedures. I am sorry for this and I apologise for it.
“My first and only aim as the Secretary of State for International Development is to put the interests of British taxpayers and the world’s poor at the front of our development work.”
Downing Street said Theresa May had spoken to Patel and “accepted her apology for her handling of the matter”.
“The prime minister met the secretary of state this morning to remind her of the obligations which exist under the ministerial code,” a No.10 spokesman said.
Downing Street also revealed May did not know about the meeting between Patel and Netanyahu until Friday.
Kate Osamor MP, Labour’s shadow development secretary, said: “Today’s statement is a desperate last-ditch attempt by Priti Patel to save her job. It has now emerged that, contrary to her statement on Friday, the Foreign Secretary was never told in advance about her meetings in Israel - which we have only now discovered included meetings with Prime Minister Netanyahu and with the Foreign Ministry.
“Not only does it look like she might have breached the Ministerial Code, she has now been caught misleading the British public. If she doesn’t now resign, then Theresa May must immediately refer the issue to the Cabinet Office for a full investigation.”
Dfid has admitted that the statement Patel gave to The Guardian on November 3 could have left given the impression Johnson knew about her trip in advance.
“Boris knew about the visit. The point is that the Foreign Office did know about this, Boris knew about [the trip],” she told the newspaper.
However Patel today admitted the foreign secretary “became aware of the visit” but “not in advance of it”.
Dfid also had to acknowledge that Patel may have led people to believe all the meetings she had in Israel had already been publically reported - when they had not.
“The Secretary of State regrets the lack of precision in the wording she used in these statements, and is taking this opportunity to clarify the position,” Dfid said.
The department has also published a list of those Patel met on her visit.