President Donald Trump on Wednesday derailed the confirmation process of his own nominee to head the nation's intelligence agencies, an extraordinary move that upended Senate efforts to renew a crucial surveillance program and fueled fresh tensions with fellow Republicans on Capitol Hill.

In an overnight social media post from the Group of Seven summit in France, Trump declared he was delaying the nomination of federal prosecutor Jay Clayton as director of national intelligence just hours ahead of his scheduled hearing, despite bipartisan praise for the nominee and Republican efforts to speed him through the confirmation process.

Senate Intelligence Committee Chairman Tom Cotton, R-Ark., said Republicans would go ahead with the Clayton hearing anyway, "unless the president directs him not to appear or withdraws his nomination." But later he postponed the hearing, saying it was "regrettable" that Trump had directed Clayton not to appear.