The threat from dissident republicans remains severe, Justice Minister Alan Shatter has said.
The minister warned that terror groups pose a risk to the security and existence of the Republic as well as Northern Ireland.
"The Garda assessment, shared by the PSNI, in relation to the terrorist threat level in Northern Ireland is that it is regarded as severe," Mr Shatter said.
"While the threat level in this jurisdiction may be different, it is imperative that our laws and our police are properly equipped to deal with the threat, whether in this jurisdiction or Northern Ireland.
"Let no-one be under the illusion that these groups do not have designs on this State as well as on Northern Ireland."
Mr Shatter released the security assessment as the Government moved to renew anti-terror legislation, the Offences Against the State (Amendment) Act 1998, to deal with terrorist suspects and groups.
Intelligence services have warned that dissidents are aligned to the Real IRA, which bombed Omagh in 1998, Oglaigh na hEireann, Continuity IRA and the new IRA.
The laws were introduced in the wake of the Omagh atrocity which left 29 people dead.
Mr Shatter added: "The 1998 Act grew out of our own domestic troubles. However, its provisions form an essential element of the State's response to the threat of terrorism from any source.
"We cannot ignore the growth in recent years of the international terrorist threat. In co-operation with our EU partners, we must continue to counteract any threat from such sources."