Even by the standards of the last few months, it has been a tense 24 hours in Washington as the Iraq diplomatic endgame reaches its probable climax.
Powell remained tight-lipped
The first sign that there was something unusual going on in Washington began at lunchtime on Thursday, when President Bush unexpectedly cancelled a St Patrick's Day lunch at the Capitol with the Irish Prime Minister, Bertie Ahern.
The decision was so sudden that press and protocol detail were already seated in the presidential motorcade about to depart when they were told the president was staying behind.
It turned out that he had decided to take an urgent call from UK Prime Minister Tony Blair, who has been growing increasingly concerned about the possible failure of the UK-sponsored UN resolution.
To the Azores
The fruits of that conversation became apparent the next morning, when Mr Bush chose the symbolic setting of the White House Rose Garden - where the Oslo peace agreement was unveiled - to signal his renewed commitment to the Middle East peace process, flanked by a silent Secretary of State Colin Powell.
Earlier, it had been announced that Mr Bush would be flying to the Azores for a hurried summit with his closest allies on the UN Security Council on Sunday.
Mr Bush took no questions, and it was left to White House national security advisor Condeleeza Rice - who had gone to the Arab television station al-Jazeera for an interview about the new initiative - to explain the purpose of the emergency summit.
The press moved quickly, with a dozen news camera crews waiting for Dr Rice as she emerged for the impromptu press conference on K Street, as well as curious members of the public behind quickly-assembled yellow police tape.
The leaders' aim is "to think about ways in which the UN security process can come to a conclusion... the moment of truth is coming here," she said, taking a few questions from the reporters' scrum before her motorcade swept away.
Tensions were also high at the regular press briefing by White House press secretary Ari Fleischer, who explained that the US did not need a new UN resolution, "but it is important to our allies, so it is important to us".
He said that there was no need for the president to have announced the summit, "as there was no chance that the press would fail to notice" the event and ask him questions.
There is likely to be little news access to the Azores summit, held on a remote military airbase on a mid-Atlantic island
The president, meanwhile, departed for his weekly retreat in the Maryland countryside, Camp David, before flying on Sunday.
But there is likely to be little news access to the Azores summit, held on a remote military airbase on a mid-Atlantic island, with only a few press pool journalists likely to be allowed to attend.
The sudden changes of plan, and the tightening of access, is a sign of the ratcheting tension as the crisis moves to its climax.
There have been weeks of waiting in Washington, as a decision on whether to go to war has been postponed and new deadlines set.
But with no sign of a breakthrough on the diplomatic front, this weekend may well prove a key decision point.