By Noah Barkin

BERLIN (Reuters) - World leaders pledged to work with Donald Trump after his shock victory in the U.S. presidential election but some officials expressed alarm that the vote could mark the end of an era in which Washington promoted democratic values and was seen by its allies as a guarantor of peace.

Trump, the real estate magnate and former reality TV star, sent conciliatory signals in his first remarks since his stunning upset of Democratic rival Hillary Clinton, pledging to seek common ground with America's partners, not conflict.

Governments in Britain, China, Germany, Israel, Japan, Russia and Turkey all congratulated Trump and said they would work with him.

"It is not an easy path but we are ready to ready to do our part and do everything to return Russian and American relations to a stable path of development," said Russian President Vladimir Putin, for whom Trump expressed admiration during the election campaign.

Israel's Benjamin Netanyahu said he hoped to reach "new heights" in bilateral ties under Trump. And British Prime Minister Theresa May said the "enduring and special relationship" between Britain and the United States would remain intact.

But other officials, some of them with senior roles in government, took the unusual step of denouncing the outcome, calling it a worrying signal for liberal democracy and tolerance in the world.

"Trump is the pioneer of a new authoritarian and chauvinist international movement. He is also a warning for us," German Vice Chancellor Sigmar Gabriel said in an interview with the Funke newspaper group.

During his election campaign, Trump expressed admiration for Russia's Putin, questioned central tenets of the NATO military alliance and suggested that Japan and South Korea should develop nuclear weapons to shoulder their own defense burden.

He has vowed to undo a global deal on climate change struck by world powers in Paris last year, ditch trade deals he says have been bad for U.S. workers, and renegotiate the nuclear deal between Tehran and world powers which has led to an easing of sanctions against the Islamic Republic.

But U.S. allies admit to being unsure whether Trump will follow through on all of the foreign policy pledges he made during the campaign.

Iran's Foreign Minister Javad Zarif urged Trump to stay committed to the Iran deal.

His South Korean counterpart expressed hope that Trump would maintain current U.S. policy of pressuring North Korea over its nuclear and missile tests.

The South Korean government was concerned Trump may make

unpredictable proposals to North Korea, a ruling party official

said in Seoul, quoting top national security officials.

A Japanese government official, speaking before Trump clinched the election, urged him to send a message as soon as possible to reassure the world of the United States' commitment to its allies.

"We are certainly concerned about the comments (Trump) has made to date about the alliance and the U.S. role in the Pacific, particularly Japan," the Japanese official said,

Some leaders are smarting from insults that Trump doled out over the past months. He called Chancellor Angela Merkel "insane" for allowing a million migrants into the country last year, unfavorably likening his opponent Clinton to the German leader.

"We're realizing now that we have no idea what this American president will do," said Norbert Roettgen, a conservative ally of Merkel and head of the German parliament's foreign affairs committee, told German radio. "Geopolitically we are in a very uncertain situation."

But like-minded right-wing European parties that are hoping to make inroads of their own in 2017, an epic election year in which Germany, France, the Netherlands, and possibly Italy and Britain, could hold elections, hailed Trump's victory.

"Their world is falling apart. Ours is being built," Florian Philippot, a senior figure in France's far-right National Front (FN), tweeted.

Prominent British historian Simon Schama described a Trump victory and Republican control of both the Senate and U.S. House of Representatives as a "genuinely frightening prospect".

"NATO will be under pressure to disintegrate, the Russians will make trouble, 20 million people will lose their health insurance, climate change (policies) will be reversed, bank regulation will be liquidated. Do you want me to go on?," Schama told the BBC.

"Of course it's not Hitler. There are many varieties of fascism. I didn't say he was a Nazi although neo-Nazis are celebrating."

(Reporting by Reuters bureaus in Europe, Asia and the Americas; Editing by Sonya Hepinstall and Angus MacSwan)