Russian officials and politicians have lauded Donald Trump's inauguration, hoping it will herald a period of better ties with the US.
Revellers in Moscow and elsewhere gathered for celebrations as bar and club owners sought to cash in on public excitement.
Mr Trump's promises to fix ravaged relations with Moscow have elated Russia's political elite following spiralling tensions with Washington over the Ukrainian crisis, the war in Syria and allegations of Russian meddling in the US elections.
While Mr Trump's policy towards Russia is as yet unclear, prime minister Dmitry Medvedev said that "we are hoping that reason will prevail".
"We are ready to do our share of the work in order to improve the relationship," Mr Medvedev said on Facebook.
A hundred Trump sympathisers, nationalist activists and spin doctors gathered at a hipster party location several hundred metres away from the Kremlin to celebrate.
An hour before Mr Trump took to the stage in Washington, the sound of opening champagne bottles echoed in the vaulted hall of the former telegraph building.
The party was co-sponsored by the conservative Tsargrad TV channel, which is led by ultra-right ideologue Alexander Dugin.
"Yes, it's a holiday," said Dmitry Rode, a communications executive, with a glass of champagne in his hand.
"We all hope that relations between our countries and, more importantly, between our peoples will help to develop our economy. We're neighbours, we're just 50 kilometres away from each other."
Political analyst Stanislav Byshok said it is probably the first time it is someone else, not the US embassy, that is hosting an inauguration party.
"It's weird, but it's great, and for the first time ever Russians are applauding the victory of a US presidential candidate, it's a sign of the times," he said.
"For the past years we have had a very tense relationship so when a person who is perceived in Russia as being neutral to Russia and who is realistic about foreign policy was elected, it was greeted with joy."
Mr Trump's praise for Russian president Vladimir Putin has raised expectations that he could move to normalise ties, though Mr Trump has not articulated a clear policy and some of his cabinet nominees have made hawkish statements on Russia.
Dmitri Trenin, director of the Carnegie Moscow Centre, predicted that Russia will face a pragmatic but very tough partner in Mr Trump.
"Russia's potential is incomparable to that of the United States," he said, adding that Moscow will have to apply a lot of skills "to play from the position of weakness and not lose".
Despite the uncertainty, many Russians looked at Mr Trump's presidency with high hopes, and some nightclubs and bars staged parties to celebrate the inauguration.
At one Moscow nightclub, several dozen people began toasting Mr Trump late on Thursday.
Willi Tokarev, 82, a singer who emigrated to the US in the mid-1970s and later became a music legend in Russia, topped the entertainment bill with his song Trumplissimo America!
"Trump, Trump, symbol of America. Trump, Trump, he's really president," the mustachioed Tokarev sang on a tiny stage with Russian and American flags hanging behind him.
Across from the US embassy compound in central Moscow, the Russian army store put up a poster with Mr Trump's picture, offering inauguration day discounts of 10% for Americans.
There is a broad feeling in Russia's political and business elites that relations with Washington cannot get any worse.
"Russia hopes that under Trump there will be no ideology, no attempts to lecture about democracy, human rights and rights of smaller nations around its borders ... but primarily deal with economic issues in a businesslike way and even tacitly divide spheres of influence," said Alexei Arbatov, a senior researcher with the Institute of World Economy and International Relations, a government-funded Moscow think tank.
"Putin and Obama spoke different languages, they didn't understand one another. There is a hope that Trump and Putin will speak the same language, even though their positions may differ."
Speaking at the World Economic Forum in Davos, Switzerland, Russian deputy prime minister Igor Shuvalov voiced hope that Mr Trump will work with Mr Putin on solving the Ukrainian crisis and other problems, but warned against expectations of quick progress.
"Difficulties will remain," he said.
Andrei Kuzyaev, a Russian oil tycoon who now heads ER Telecom, a leading broadband provider, said he expects Mr Trump to "switch from political propaganda to action".
In the Kremlin-controlled parliament, many expressed similar expectations that Mr Trump will be driven by pragmatic interests.
Leonid Slutsky, the head of the foreign affairs committee in the lower house of parliament, expressed hope that Mr Trump will move to establish constructive ties with Moscow, but cautioned that there is no "magic button" to instantly achieve that.
"We expect a slow but steady revival of our relations," he said.
Many ordinary Russians appeared to share expectations of a thaw in US-Russian ties.
"I hope that everything will be good and we will be friends as always, as it was before," said 52-year-old Elena Tetyorkina, from Norilsk in the Far North.
Mr Medvedev, who served as president in 2008-2012 when Mr Putin had to shift into the premier's seat due to term limits, presided over a period of warmer ties during Mr Obama's first term.
Mr Medvedev sharply criticised the outgoing administration for ruining relations with Moscow by attempting to treat Russia like a "banana republic" and relying on "brute force and sheer pressure" in its dealings with Moscow.
"Conclusion: The Obama administration has destroyed relations between the United States and Russia, which are at their lowest point in decades," Mr Medvedev said.
He denounced the sanctions the US and its allies imposed on Russia over its action in Ukraine, saying that "it doesn't get any dumber than restricting entry to the United States for the leadership of the Russian parliament, ministers and businessmen, thus deliberately reducing the possibility of full-fledged contacts and closing the window to co-operation".