Bush, NATO focus on Iraq
President Bush reviews the military honor guard with Turkish President Ahmet Necdet Sezer.
NATO is expected to agree to help train Iraqi troops.
CNN's Alphonso Van Marsh reports on the Turkish response to the hostages in Iraq.
Turkey wants U.S. help in heading off a Kurdish state in northern Iraq.
ISTANBUL, Turkey (CNN) -- President Bush arrived Sunday in Istanbul to attend the NATO summit with hopes of persuading the international body to help train Iraqi forces after Iraqis officially take control of their country on Wednesday.
Bush's visit comes amid a report from Arab TV network Al-Jazeera that Iraqi terrorists kidnapped three Turkish citizens and threatened to behead them in 72 hours if Turkey does not pull its companies out of Iraq.
According to the text read by the Al-Jazeera anchor, the kidnappers called on the people of Iraq to denounce Bush's visit to Turkey and to insist Turkish companies leave Iraq.
Tens of thousands of Turks, many chanting anti-Bush slogans, demonstrated in the streets of Istanbul on Sunday.
Bush traveled to Ankara, Turkey, on Saturday for advance meetings with Turkish leaders.
U.S. Secretary of State Colin Powell, who is traveling with the president, said Bush assured Turkish Prime Minister Recep Tayyip Erdogan the United States is doing all it can to secure the safe release of the hostages.
In his meeting with Erdogan, Bush also reiterated his backing for Turkey's European Union membership bid and said the country was a model for Muslim democracy.
"I appreciate so very much the example your country has set on how to be a Muslim country and at the same time a country which embraces democracy and rule of law and freedom," Bush said.
In an effort to stem terrorist acts, Iraq's interim Prime Minister Iyad Allawi is asking NATO to help train Iraqi forces as his country takes the reins of power on Wednesday.
In Ireland on Saturday for a summit with European Union leaders, Bush urged NATO to accept Allawi's request.
"They have to have their forces, their police well trained and well prepared to meet the threat of the few who want to derail the ambitions of the many," the U.S. leader said.
Powell expressed confidence Sunday that NATO will give a positive response to Allawi's request for assistance in training troops.
"We'll certainly know tomorrow when NATO meets, but every indication I have now is that NATO is coming together to say that they would be willing to provide police and military training to Iraqi forces," Powell told CNN's "Late Edition with Wolf Blitzer."
National security adviser Condoleezza Rice told ABC's "This Week" that there is a "very good chance" that NATO will respond positively to Allawi's request.
Allawi is considering a state of emergency to enforce law in Iraq after the June 30 handover.
NATO Secretary-General Japp de Hoop Scheffer expressed confidence that Allawi's request will be debated and approved at Monday's summit in Istanbul.
"President Allawi will have an answer on what he has asked," de Hoop Scheffer said Saturday.
De Hoop Scheffer said NATO ambassadors reached an initial agreement on Allawi's request at a meeting in Brussels, Belgium, on Friday.
On Sunday, de Hoop Scheffer said NATO instructors could work both inside and outside Iraq to train Iraqi forces.
"I cannot give you details on numbers as yet," he said. "NATO is going to do training. Training is essential. ... It can be both inside and outside the country."
In an interview with Italy's Il Sole 24 Ore daily, de Hoop Scheffer said the world must not stand by and watch Iraq "go up in flames."
He said NATO must also remain committed to Afghanistan, keeping its promise to the government there, Reuters reported.
"The international community in its entirety, not just NATO, cannot allow itself to see Afghanistan return to being a safe haven for terrorism," he said.
"The same goes for Iraq, which cannot go up in flames amid general indifference. Because the entire region would be destabilized."
The 26-member alliance also will look for links with the Arab nations of the Middle East to help stabilize the region.
Monday's summit comes just ahead of the June 30 handover in Iraq, and a key question in Istanbul will be whether NATO should formally take on a new role in Iraq.
Seventeen member nations are already in Iraq individually helping the U.S.-led coalition. However, NATO members such as Germany and France opposed the war and say they will not send troops.
A new U.N. resolution that recognizes Iraq's interim government has begun to bridge the gap.
Bush's visit and the NATO summit are taking place under heavy security, after a devastating bomb blast killed four people and wounded a dozen others on Thursday.
Turkey has deployed more than 25,000 security forces and established security perimeters around the summit venue, closing some 200 streets and re-routing commuter ferry boats away from ports near the site.
Oil tankers have been banned from the Bosporus Strait, the waterway that connects Istanbul's Asian and European sides.
Summit organizers fear a repeat of last November's terror attacks in Istanbul, when four suicide bombers killed more than 60 people, including the British consul.
CNN's Alphonso Van Marsh and Robin Oakley contributed to this report