For the Conservatives, election results have been shocking since they lost 12 seats of sitting MPs forcing them to go for a coalition government.
When a reporter asked for his reaction to the election in Britain, Trump said, "Surprising".
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'The mandate she's got is lost Conservative seats, lost votes, lost support and lost confidence, ' he said.
With only 17 of the 650 seats still to declare, the results largely bore out the exit poll, which predicted the Conservatives would get 314 of the 650 House of Commons seats, down from 330.
The result looks set to trigger a period of political uncertainty and could throw Britain's negotiations to leave the European Union, due to start June 19, into disarray.
"As we're the party who won the most seats and most votes, we're the only party in a position to do that".
Conservative MP Anna Soubry was the first in the party to disavow Ms May in public, calling on the Prime Minister to "consider her position".
John McDonnell, Labour's shadow Chancellor, said the party would put forward a Queen's Speech and urge other parties to support it.
British voters narrowly approved a referendum a year ago to exit the European Union, and Thursday's election raised the prospect that the loss of Conservative seats represented buyers remorse over the Brexit decision.
Speaking to media outside Number 10, Ms May spoke as certainly as though her Conservative party had won an absolute majority - which it hasn't.
"It's important to have a Government that can take the Brexit negotiations through".
"The British have spoken, they have voted, and have given the Conservative Party a majority, albeit a simple majority, which is something of a surprise", Philippe told Europe 1 radio.
She now risks more opposition to her Brexit plans from inside and outside her party. He said voters had rejected her Brexit plan.
"Britain is a member of North Atlantic Treaty Organisation, so we have a lot of shared challenges to deal with, and that's the spirit we want to carry out these negotiations in". I said at the start this election was wrong.
The Czech prime minister said Friday that Britain should not be granted any extension on the two-year deadline for the Brexit talks.
The Labour leader vowed to fight his Tory rival's attempt to run a minority government in an interview with the Sunday Mirror. However, Labour has fought to water down May's Brexit strategy which could make it easier to reach a compromise with either the Liberal Democrats, which has ruled out any coalition, or the pro-European SNP.
Late in the campaign, Britain was hit by two terror attacks that killed 30 people in Manchester and London, temporarily shifting the focus onto security issues.