US Ambassador Zalmay Khalilzad on Thursday told reporters in Baghdad: "Coalition forces... are planning to look at this problem and see what could be done to fix the security for the diplomats."
"It's very important for foreign diplomats who come here to have a sense of security," he said.
Khalilzad spoke a day after al-Qaida announced in an internet statement that it had killed two Algerian diplomats - including the country's chief envoy - because of their government's ties to the United States and its crackdown on Islamic organisations.
Wednesday's statement said the envoys had been killed because of the Algerian government's repression of Muslims in their North African country.
Al-Qaida blames Algeria
"We won't forget what Algeria did to Muslims, by killings, destruction and spilling their blood," said the statement.
"We won't forget what Algeria did to Muslims, by killings, destruction and spilling their blood"
Website statement attributed to Al-Qaida
Chief envoy Ali Belaroussi and diplomat Azzedine Belkadi were kidnapped just outside their embassy in Baghdad's western neighbourhood of Mansour.
Al-Qaida in Iraq also claimed responsibility for the killing of Egypt's top envoy and the attempted abduction of two other diplomats in a campaign to undercut support for the new Iraqi government within the Arab and Muslim world.
The United States had been urging Arab and Muslim countries to deepen their diplomatic ties to Baghdad - a strategy which now seems at risk after the attacks on diplomats.
Khalilzad said no final decision had been made on offering protection, and some Arab diplomats may fear that the presence of US forces around diplomatic missions might actually draw attacks.
Both the Algerians and the Egyptian diplomat had no personal bodyguards when they were abducted.
Iraqi Foreign Minister Hoshyar
Zebari denounced the killings
One of the two victims Belaroussi had told colleagues he didn't feel the need for security because of Algeria
's good relations with the Iraqi people and its opposition to the US-led invasion.
"We have not accepted taking on the mission at this point," Khalilzad said. "But what we've agreed is, we will look at this, see what the problem is, and what the options might be for assisting with this mission."Iraq's foreign minister Zebari denounced the killings as a "barbarous act... by a fundamentalist terrorist group", in comments to reporters.
"Their goal is to sever ties between Iraq and Arab and Muslim countries," he said, adding: "We shall avail ourselves of the presence of (US-led) coalition troops to offer diplomats better protection".