THE White House has expressed "outrage at the callous murder" of the two RUC officers in Lurgan and hinted that its patience with IRA/Sinn Fein is fast running out.
President Clinton, in a written statement, said: "I am outraged by the callous murder by the IRA of two policemen in Northern Ireland. I condemn this brutal act of terrorism in the strongest possible terms."
"There is nothing patriotic or heroic about these cowardly killings," said Mr Clinton.
He warned against retaliation.
"Further violence can only play into the hands of those responsible for the vicious murders."
He also pledged to keep working for peace. "I will continue to do all I can to support the efforts of the political leaders participating in the Belfast peace talks."
Senator Edward Kennedy has said that "now is the moment of truth for Sinn Fein. They must produce a ceasefire or else join in condemning the violence".
In one of its harshest statements about IRA attacks, the White House said that while the IRA "has claimed responsibility for what is ultimately an outrageous act of cowardice, an outrageous act of terrorism, no one should ever make the mistake of thinking that action of this kind represents anything equating to patriotism".
The White House press secretary, Mr Mike McCurry, said it was probably the exact opposite of patriotism and heroism to seek out and shoot two law enforcement officers in the back".
Asked if the US would continue contacts with Sinn Fein, Mr McCurry said the US government had had contacts with those parties that have been "helpful to the peace process and we will continue contacts that are helpful to the process but sooner or later it becomes clear who is willing to help the process and who is not".
He said "there is a point where those who want to be with history and with peace need to come forward and do what they know they must and are required to do".
This was seen as the White House not yet being ready to close the door entirely on its covert contacts with Sinn Fein but fast reaching that point.
Last week, President Clinton had already expressed "serious concern over IRA actions in Belfast and Derry and appealed for a new ceasefire.
The murder of the two RUC officers can only be seen here as a particularly ruthless response to this appeal.
There is bewilderment in the US administration at the IRA's actions at a time when there were hopes that the change of government in London would lead to a breakthrough in the stalled peace process.