KIRKUK, Iraq, (Reuters) – U.S. Secretary of State Condoleezza Rice, on a visit overshadowed by a Turkish incursion into northern Iraq, called on Iraqi leaders on Tuesday to urgently implement a national reconciliation roadmap.

Turkish troops crossed overnight into the Iraqi Kurdish province of Dahuk, about 200 km (120 miles) from the city of Kirkuk, where Rice’s plane first touched down. A Turkish military official said they clashed with separatist guerrillas.

A senior Iraqi Kurdish official said on Tuesday evening the troops had since withdrawn. It was the latest in a series of raids against guerrillas of the separatist Kurdistan Workers Party (PKK) who shelter in the semi-autonomous Kurdistan region.

While not commenting directly on the incursion, Rice told a news conference in Baghdad that “no one should do anything that threatens to destabilise the north”, referring to Kurdistan, Iraq’s most stable region. The incursion was a reminder that while violence in Iraq has dropped by 60 percent since June, security is fragile and Iraq still faces threats both from within and without.

During Rice’s visit, a suicide bomber wearing an explosive vest killed 14 people when he targeted a coffee shop in a village north of Baghdad. It was the worst incident in a day of violence in which at least 28 people were killed.

Making her eighth visit as secretary of state, Rice urged leaders of Iraq’s main political blocs to implement an Aug. 26 national reconciliation pact. “I have strongly encouraged the leaders with whom I have met today … that there be urgent implementation of that Aug. 26th agreement, that there be urgent attempts to … make certain that the legislative agenda is moving forward,” she said. “We all understand that democracy is hard and that it takes time. But … when people elect their leaders, they expect them to make very strong efforts,” she said.

Overall security in Iraq has improved due to the deployment or “surge” of 30,000 more U.S. troops, an uprising by Sunni Arab tribes against al Qaeda militants and a six-month ceasefire declared by Shi’ite cleric and militia leader Moqtada al-Sadr. But Prime Minister Nuri al-Maliki’s Shi’ite-led government remains paralysed by deep divisions and mistrust between leaders of Iraq’s different religious sects and ethnic groups. It has made little headway in passing laws aimed at reconciliation. “We need a political and legislative surge to augment and strengthen these gains,” Iraqi Foreign Minister Hoshiyar Zebari acknowledged at the news conference with Rice.

In one sign of the improved security in the capital, Rice lunched at the central Baghdad home of President Jalal Talabani in what U.S. troops call the “Red Zone” — all of Baghdad outside the “Green Zone” government and diplomatic compound.

U.S. officials said Rice’s planned meeting with Maliki on Tuesday evening was delayed because her motorcade was held up when a sniffer dog smelled something suspicious.

Rice first flew into Kirkuk, a mixed city of Kurds, Arabs and Turkmen 250 km (155 miles) north of Baghdad. The city is seen as the next powderkeg in Iraq, with Kurdish nationalists demanding it be included in their largely autonomous region. Her decision to start her visit in Kirkuk appeared part of the new U.S. policy of focusing more on fostering reconciliation at a local and regional level. Kirkuk, with its huge oil reserves and potential for destabilising violence, is key.

Iraq’s minority Kurds, who control the Kurdistan region, see Kirkuk as their historical capital, but Arabs encouraged to move there under Saddam Hussein want it to remain under the sway of the Baghdad government.

A clause in Iraq’s constitution provides for a referendum to be held there by Dec. 31 to determine whether the area joins Kurdistan, but it has been delayed because of the deep divisions among Arabs and Kurds.

A U.S. official said the U.N. special representative to Iraq, Steffan de Mistura, had secured an agreement between the different parties in the past few days to allow the U.N. to play an enlarged role in moving the referendum process forward.