President Trump announced Friday that Bahrain would establish full diplomatic relations with Israel, following the United Arab Emirates, in another sign of shifting Middle East dynamics that are bringing Arab nations closer to Israel, isolating the Palestinians and positioning Trump as a campaign-season peacemaker.

Trump announced the news on Twitter, releasing a joint statement with Bahrain and Israel and calling the move “a historic breakthrough to further peace in the Middle East.’’ Speaking to reporters, his son-in-law, Jared Kushner, who helped broker the deal, noted that it came on the anniversary of the Sept. 11 terrorist attacks and said it would “honor the memory’’ of Americans killed by actions arising from hatred and conflict in the Middle East.

The announcement came after a similar one last month by Israel and the UAE that they would normalize relations with each other, on the condition that Prime Minister Benjamin Netanyahu of Israel not follow through with plans to annex portions of the West Bank. Trump administration officials said they hoped that agreement would encourage other Arab countries with historically hostile — though recently thawing — relations with Israel to take similar steps.

It also comes as Trump, who is burnishing his accomplishments before the election in November, positions himself as a maker of historic peace deals, even as analysts call his claims to Nobel Prize-worthy diplomacy overstated. (Among other things, they note, neither the UAE nor Bahrain were in conflict with Israel; in fact, they had been moving into a de facto alliance with the Jewish state.) On Saturday, Secretary of State Mike Pompeo will preside over new peace talks devised to end the 19-year war in Afghanistan. The White House recently hosted Balkan leaders in pursuit of an end to longtime tensions between Serbia and Kosovo.

Bahrain’s move was not unexpected: The tiny Persian Gulf kingdom was widely seen as the low-hanging fruit to be picked if all went well in the aftermath of the Emiratis’ announcement, analysts said.

Israel would always welcome the addition of another Arab country to the shortlist of those with diplomatic ties, but in Jerusalem the announcement by Bahrain landed with neither the surprise nor the weight of the Emirati decision.

“Any Arab country is very important, for sure,’’ said Amos Gilead, a retired Israeli major general who leads the Institute for Policy and Strategy at the Interdisciplinary Center Herzliya. “It’s another precedent. But with all due respect, when you are small, you are small.’’

But Bahrain has an outsize significance, said Kirsten Fontenrose, a former National Security Council senior director for Gulf affairs at the Trump White House who is now a director at the Atlantic Council. She noted that Bahrain was a close ally of Saudi Arabia.

“Its importance is mostly because it’s an indication that the new leadership in Saudi Arabia supports normalization, because Bahrain doesn’t make a foreign policy move without Saudi Arabia’s express permission,’’ Fontenrose said.

Still, Democrats and Middle East analysts questioned the administration’s self-congratulatory tone, given that Israel’s relations with Gulf Sunni Arab nations have been warming for years, driven by a common animus toward Shiite Iran.

“This latest agreement by itself is an encouraging sign of progress in a region that has been racked with conflict and civil wars,’’ said Brian Katulis, a senior fellow and Middle East expert at the liberal Center for American Progress. “But it’s hard to credit the Trump administration with this deal.’’

The agreement was brokered in large part by Kushner. Speaking to reporters Friday, he said Bahrain’s move would “separate the Palestinian issue from their own national interests, from their foreign policy, which should be focused on their domestic priorities.’’

Asked whether the United States or Israel had made any concessions to Bahrain in exchange for the agreement, Kushner did not respond directly. He said that officials from Bahrain would join a ceremony at the White House Tuesday to sign the deal between Israel and the UAE.