WASHINGTON – The Irish Republican Army announced yesterday that it has given up its remaining weapons, acceding to long-standing demands from Dublin and London that the outlawed terrorist group disarm.

A statement yesterday from a former Canadian general, John de Chastelain, who has overseen this process since 1997, confirmed that stocks of heavy artillery, anti-aircraft weaponry, flamethrowers, and the like have been decommissioned.

The weapons decommissioning, as it is called in the accords that stopped the sectarian fighting in Northern Ireland, has been one of the last remaining steps toward reconciling the conflict that plagued the Protestant minority and Catholic majority there for generations.

A spokesman for the State Department, Sean McCormack, yesterday called the announcement a “step forward on the path toward a sustainable political settlement in Northern Ireland.” He used the opportunity to urge other paramilitary organizations to follow the IRA’s lead and disarm.

“It is an historic move. It is something that no one would have thought possible 10, 15, 20 years ago,” a co-chair of the House ad hoc committee on Irish affairs, Rep. Peter King, a Republican of New York, said in an interview yesterday. “It’s important that the British government take advantage of this now and convince the unionists to cooperate with the Good Friday Accords and go into a power-sharing government,” the Irish-American lawmaker – whose great-uncle was a member of the IRA – said.

Senator Kennedy, a Democrat of Massachusetts, also greeted the news of the decommissioning of weapons as a historic breakthrough. “Hopefully, this dramatic and historic step toward peace will be embraced by the unionist community and become a new dawn for the peace process, so that the all-important restoration of the Northern Ireland Assembly can take place as soon as possible,” Mr. Kennedy said in a statement.

But the announcement yesterday was greeted with skepticism by longtime foes of the IRA and its political counterpart, Sinn Fein, which has lately distanced itself from the armed group.

The leader of the Protestant Democratic Unionist Party, Ian Paisley, yesterday complained that the process of decommissioning was not verifiable. “Instead of openness, there was the cunning tactics of a cover-up, the complete failure from General John de Chastelain to deal with the vital numbers of decommissioning,” he said. Other Protestant leaders complained that the IRA was able to veto members of the committee that oversaw the disarming, stacking the jury in its favor.

An editor at large for the National Review and a former speech writer for Prime Minister Thatcher, John O’Sullivan yesterday warned that the IRA has in the past claimed to have disarmed only to hold onto more weapons.

“One can’t be too hopeful. This is the fourth or fifth historic declaration of this kind,” he said. “Each time the London and Dublin governments have given concessions. Each time the IRA has carried on killing, maiming, and running criminal rackets. If this time is different, we must hold Sinn Fein and the IRA to normal democratic standards, which means no rackets and no intimidation.”