U.S. Vice President Mike Pence on Saturday brought a message of support for Europe from Donald Trump, but failed to wholly reassure allies worried about the new president's stance on Russia and the European Union.

In Pence's first major foreign policy address for the Trump administration, he told European leaders that he spoke for Trump when he promised "unwavering" commitment to the NATO alliance.

"Today, on behalf of President Trump, I bring you this assurance: the United States of America strongly supports NATO and will be unwavering in our commitment to this transatlantic alliance," Pence told the Munich Security Conference, offering "greetings" from the president.

But he also repeated U.S. calls for more defence spending in return: "As you keep faith with us, under President Trump we will always keep faith with you."

While Poland's defence minister praised Pence, many others, including France's foreign minister and U.S. lawmakers in Munich, remained sceptical that he had convinced his allies that Trump would stand by Europe.

Trump's contradictory remarks on the value of the North Atlantic Treaty Organisation, scepticism over the 2015 deal to curb Iran's nuclear ambitions and an apparent disregard for the future of the European Union have left Europe fearful for the seven-decade-old U.S. guardianship of the West.

After Pence spoke, former NATO deputy secretary general Alexander Vershbow, who is American, summed up the mood, telling Reuters: "Many in this hall are still asking if this is the real policy."

Pence, whose meeting with German Chancellor Angela Merkel was described by German aides as "very friendly", also marked out a divide on Iran, which the European Union sees as a business opportunity following the nuclear deal.

Pence called Tehran "the leading state sponsor of terrorism", language never used by European officials. Pence's strident vow to consign Islamist militants "to the ash-heap of history" also raised eyebrows, European officials said.

U.S. Homeland Security Secretary John Kelly defended Trump's directive suspending travel to the United States by citizens of seven mostly Muslim countries, since blocked by U.S judges, which was condemned by EU governments.

Kelly said he would produce a "tighter, more streamlined version" soon, saying: "We need to find ways to vet in a more reliable way to satisfy us that people coming to the United States are coming for the right reasons."

TWO U.S. GOVERNMENTS?

French Foreign Minister Jean-Marc Ayrault expressed disappointment that Pence's speech did not mention the European Union, although the vice president will take his message to EU headquarters in Brussels on Monday.

"I hope that we will have a clear response (in Brussels) ... because Donald Trump has said he was overjoyed by the Brexit and that there would be others," Ayrault said, referring to Britain's decision to leave the European Union.

U.S. Senator Chris Murphy, a member of the opposition Democrats, said he welcomed Pence's address but saw two rival governments emerging from the Trump administration.

Pence, Trump's Defense Secretary Jim Mattis and his foreign minister Rex Tillerson all delivered messages of reassurance on their debut trip to Europe.

But events in Washington, including a news conference in which Trump branded accredited White House reporters "dishonest people", sowed more confusion.

"I like a lot of what I heard from Vice President Pence," Murphy told Reuters. "It's just hard to square that speech with everything Donald Trump is doing and saying," citing an assault on the free press.

The resignation of Trump's security adviser Michael Flynn over his contacts with Russia on the eve of the U.S. charm offensive in Europe also tarnished the message Pence, Mattis and Tillerson were seeking to send, officials told Reuters.

U.S. Republican Senator John McCain, a Trump critic, told the conference on Friday that the new president's team was "in disarray".

The United States is Europe's biggest trading partner, the biggest foreign investor in the continent and the European Union's partner in almost all foreign policy, as well as the main promoter of European unity for more than 60 years.

TEPID APPLAUSE

Pence, citing a trip to Cold War-era West Berlin in his youth, said Trump would uphold the post-World War Two order.

"This is President Trump's promise: we will stand with Europe today and every day, because we are bound together by the same noble ideals – freedom, democracy, justice and the rule of law," Pence said.

Pence received little applause beyond the warm reception he got when he declared his support for NATO. His warning that the "time has come to do more" on military spending was met with an awkward silence.

The United States provides around 70 percent of the NATO alliance's funds. European governments sharply cut defence spending after the fall of the Soviet Union but Russia's resurgence as a military power and its seizure of Ukraine's Crimean peninsula has started to change that.

Baltic states and Poland fear Russia might try a repeat of Crimea elsewhere. Europe believes Moscow is seeking to destabilize governments and influence elections with cyber attacks and fake news, an accusation denied at the conference by Russian Foreign Minister Sergei Lavrov.

Pence's tough line on Russia, calling on Moscow to honour the international peace accords that seek to end the conflict in eastern Ukraine, were welcomed by Polish Defence Minister Antoni Macierewicz. Lavrov said after a meeting with his French, German and Ukrainian counterparts that there would be a new ceasefire from Feb. 20.

"Know this: the United States will continue to hold Russia accountable, even as we search for new common ground, which as you know, President Trump believes can be found," Pence said.