JERUSALEM — The backdrop for Secretary of State Mike Pompeo’s planned speech to the Republican National Convention promised to be spectacular: sweeping views of Jerusalem’s Old City, with the domes and spires of its holy sites.
But even before his plane touched down in Israel on Monday, Mr. Pompeo was being criticized there and in the United States for breaking a longstanding taboo against mixing diplomacy and partisan politics.
For President Trump, and particularly his evangelical Christian supporters, few locations have the resonance of the holy but fiercely contested city of Jerusalem.
“Looking forward to sharing with you how my family is more SAFE and more SECURE because of President Trump,” Mr. Pompeo wrote on Twitter. “See you all on Tuesday night!” He ended the post with a U.S. flag emoji.
Soon after landing in Israel, Mr. Pompeo met with Prime Minister Benjamin Netanyahu, a conservative who has forged a tight alliance with Mr. Trump and the Republican Party.
In remarks after the meeting, both men addressed their joint stance against Iran, praised the strength of the United States-Israel alliance and celebrated the recent diplomatic coup of an Israeli-Emirati accord brokered by the Trump administration. The United Arab Emirates is the first Persian Gulf country to agree to establish formal relations with Israel.
Mr. Netanyahu said the deal ushered in “a new era where we could have other nations join.” Standing alongside Mr. Pompeo at his office in Jerusalem, he said: “We discussed this, and I hope we’ll have good news in the future, maybe in the near future. I think it makes sense.”
Mr. Pompeo said he had come in part to congratulate the Israelis and Emiratis.
“What’s taking place here is deeply consistent with what President Trump set out to do: create a more stable, more prosperous Middle East,” he said. “This is a really good step in that direction.”
Neither of them addressed the brewing political dispute about Mr. Pompeo’s plan to record a video address from a rooftop location in Jerusalem, possibly the King David Hotel, to be shown later at the Republican convention.
There is little secret about why Mr. Pompeo would choose such a setting for his speech. One of Mr. Trump’s signature foreign policy actions was recognizing Jerusalem as Israel’s capital in 2017, and relocating the United States Embassy to the city from Tel Aviv a few months later, upending decades of American policy and flouting an international consensus.
As questions arose about the appropriateness of Mr. Pompeo’s planned speech, however, a State Department spokesperson said that Mr. Pompeo would be addressing the convention “in his personal capacity.”
“No State Department resources will be used,” the spokesperson said. “Staff are not involved in preparing the remarks or in the arrangements for Secretary Pompeo’s appearance. The State Department will not bear any costs in conjunction with this appearance.”
But Wendy R. Sherman, who served as under secretary of state for political affairs in the Obama administration, described the plan as “unprecedented and wrong.”
“At a time when peace and security in Middle East is so tough, Jerusalem should not be a prop for the RNC, and @SecPompeo should not be tarnishing the office of SecState,” she wrote on Twitter.
Halie Soifer, the executive director of the Jewish Democratic Council of America and a former national security adviser to Senator Kamala Harris, the Democratic nominee for vice president, called the planned remarks “unprecedented and highly unethical.”
Daniel B. Shapiro, the American ambassador to Israel under President Barack Obama, said that coming to the region to build on the Israel-United Arab Emirates deal and to try to add momentum to that process made perfect sense. But he said timing a visit to Jerusalem to address the Republican convention from there was “cheap, transparent politics of the lowest order.”
“It violates a core principle which is drilled into every foreign service officer from the first day of their training: that the State Department needs to conduct itself overseas above American politics,” Mr. Shapiro said.
“It may score some points with evangelical voters, and I suspect that’s what it’s designed to do,” he added.
“But it’s going to hurt Trump with Jewish voters who actually care about keeping Israel as a bipartisan issue,” Mr. Shapiro said, “and preventing it from being used as a partisan political football.”
Mr. Pompeo’s four-day tour includes planned stops in the United Arab Emirates and in Sudan and Bahrain, two other countries that have shown signs of warming ties with Israel.
The State Department said in a statement that he would meet in Sudan with Prime Minister Abdalla Hamdok and Abdel Fattah el-Burhan, the country’s top general, to discuss continued American support for the civilian-led transitional government and to “express support for deepening the Sudan-Israel relationship.”
“The U.S. commitment to peace, security, and stability in Israel, Sudan, and among Gulf countries has never been stronger than under President Trump’s leadership,” the statement read.
The deal with the United Arab Emirates raised some hackles in Israel with the revelation that the Trump administration is pushing sales of F-35 stealth fighters and other advanced weapons to the Gulf state, despite worries in Israel that such sales would weaken the nation’s strong military advantage in the Middle East. Mr. Netanyahu’s critics have questioned his assertions that he did not tacitly green-light the sales.
Mr. Pompeo said in Jerusalem that the administration would “continue to review that process,” but in a way that preserves the United States commitment to maintain Israel’s military edge. He noted the Americans’ “20-plus-years security relationship with the United Arab Emirates as well, where we have provided them with technical assistance and military assistance” to help them defend against threats from Iran.
Choosing his words carefully, Mr. Netanyahu said he did not “know of any arms deal that has been agreed upon. It may be contemplated. Our position hasn’t changed,” he added, referring to his stated opposition to advanced weapons sales to Arab countries.
Mr. Pompeo also met in Jerusalem with Defense Minister Benny Gantz and Foreign Minister Gabi Ashkenazi, both of the centrist Blue and White party.
The intersection of American and Israeli politics can be fraught for both sides, and Mr. Pompeo’s address to the Republican convention could deal another blow to international relations, further fraying the bipartisan support that Israel has long considered one of its top strategic assets.
Michael B. Oren, a former Israeli ambassador to Washington who also served as a deputy minister under Mr. Netanyahu, said that if Joseph R. Biden Jr., the Democratic candidate, won in November, “it’ll make the task all that more difficult to get us back to a bipartisan place.”
Still, experts said, the Israelis probably had little say in Mr. Pompeo’s plan to film a video for the convention in Jerusalem, and could hardly oppose it.
Mr. Netanyahu has also been charged in the past with inserting himself into American politics. He was accused of meddling in the 2012 presidential campaign by embracing the Republican challenger, Mitt Romney, in Jerusalem, and had a rocky relationship from the outset with Mr. Obama.
Before Mr. Trump recognized Jerusalem as Israel’s capital, the United States had long insisted that the city’s status be settled in negotiations between the Israelis and the Palestinians. The Palestinians claim the eastern half of the city, which Israel captured from Jordan in the 1967 war, as the future capital of an independent state. But as a result of the recognition move, the Palestinians curbed their contacts with the Trump administration and have rejected the Trump plan for resolving the Middle East conflict, which they view as biased toward Israel.
At a recent campaign rally in Oshkosh, Wis., Mr. Trump promoted the embassy move to Jerusalem, saying, “That’s for the evangelicals.”
“The evangelicals are more excited by that than Jewish people,” he added. “That’s right — it’s incredible.”