President Donald Trump found an easy rapport with Russia's Vladimir Putin
US President Donald Trump headed to Argentina Thursday for a fractious weekend of G20 summitry, cancelling planned talks with Russia's leader and boasting that his trade war with China was paying off.
Rumblings of resistance to Trump's isolationist agenda were apparent as French President Emmanuel Macron said he would convene his fellow European leaders in Buenos Aires to forge a united front on "all the challenges" faced at the G20.
Trump called off Saturday's bilateral with President Vladimir Putin at the G20, minutes after saying it would "probably" still happen despite Russia's seizure of three Ukrainian ships.
"I look forward to a meaningful Summit again as soon as this situation is resolved!" Trump tweeted, calling on Russia to return the ships and their detained crews.
Ukraine's President Petro Poroshenko retweeted Trump's change of mind and added his own comment in English: "This is how great leaders act!"
The cancellation coincided with a new eruption in the controversy over Russian meddling in the 2016 US presidential election -- an issue that also flared up when the pair held their only summit to date, in Finland in July.
Trump again ridiculed the investigation into the allegations and accused his former lawyer Michael Cohen of lying, after Cohen pled guilty to misleading Congress.
In Moscow, Kremlin spokesman Dmitry Peskov reacted frostily to Trump's cancellation, saying it would free up Putin to hold other "useful meetings" at the G20.
Ukraine's government hoped to embarrass Putin at the G20 by erecting a giant billboard outside the meeting, depicting a bleeding Kerch strait off Crimea where Russia captured the ships.
But an Argentine advertising company refused to erect the poster, Emine Dzhaparova, Ukraine's deputy information minister, said in Buenos Aires.
UN Secretary-General Antonio Guterres said Ukraine's territorial integrity should be respected and added: "I hope that escalation can be contained."
- Art of the deal -
While the Putin meeting now appears off, Trump is still slated to sit down with various leaders on the G20 margins including German Chancellor Angela Merkel, one of his firmest foreign critics.
However, Merkel's plans were disrupted by technical troubles that forced her official plane to make an emergency landing in Germany, and a spokeswoman told AFP that she would miss Friday's opening of the summit.
Topping the billing is a working dinner with Chinese President Xi Jinping, when Trump will press for wholesale reform of the world's second-biggest economy in favor of access for US companies.
After heaping huge tariffs on Chinese goods, and threatening more to come in January, Trump said a ceasefire in the trade war was "very close" -- but cast doubt on whether he even wanted one.
"I think China wants to make a deal. I am open to making a deal but frankly I like the deal that we have right now," the president said.
Referring to the China tariffs, he said: "What we have right now is billions and billions of dollars coming into the United States in the form of taxes."
However, economists and critics of the president's trade policies point out duties are paid by importers and thus constitute a tax on US industry and consumers that is not paid by China.
En route to Argentina, Xi vowed on Wednesday that China would "make a lot of efforts to speed up market access, improve the investment environment and increase protection of intellectual property."
But foreign firms in China complain that such promises are all too routine, and analysts doubt that Trump and Xi's dinner will serve up much beyond a commitment to negotiate further.
- 'Useless' -
Trump's tough talking set the stage for a contentious gathering in Argentina with the tensions over Ukraine and trade deepening fissures carved open by the US president on climate change -- an issue that nearly torpedoed last year's G20 hosted by Merkel.
It is likely to be to the fore of the meeting of European leaders called by Macron, along with demands to resist the trade protectionism now stalking the world economy 10 years after the first G20 summit was held in the throes of financial crisis.
In an interview with Argentine daily La Nacion, the French president warned against the risk of "a destructive trade war for all."
"If we do not show concrete progress, our international meetings become useless and even counterproductive," he said.
But Trump has repeatedly shown his disdain for international summitry by blocking final communiques at other recent gatherings such as the G7 and the Asia-Pacific bloc APEC.
G20 sources said climate change was emerging as the biggest stumbling block to agreement on a communique in Buenos Aires.
US opposition to collective action stands in defiance of scientists' increasingly urgent warnings that the planetary threat needs policy redress now.
With a major UN meeting on climate change starting next week in Poland straight after the G20, Guterres said "this is a make-it-or-break-it moment."