Israel’s ambassador to Washington said Sunday that his country would reject an international inquiry into last week’s deadly raid on a Turkish ship, but there was still no formal announcement from Jerusalem on the matter.

“We are rejecting the idea of an international commission,” Michael B. Oren, the ambassador, told Fox News Sunday. “We are discussing with the Obama administration the way in which our inquiry will take place.”

He added, “At the end of the day, Israel has the right, the duty, as a democracy to investigate any military activity.”

The remarks came after the United Nations secretary general, Ban Ki-moon, conveyed a proposal to Israel for an international panel to investigate the raid on the ship, which was trying to breach Israel’s naval blockade of Gaza.

The Israeli commando operation, which took place in international waters last Monday, left nine Turkish activists dead, stirring international outrage. Israel said that its soldiers opened fire only as a last resort after they encountered fierce resistance on the Turkish ship.

It was not immediately clear whether Mr. Oren was referring specifically to Mr. Ban’s proposal, and there was confusion in Israel over what the government’s position was.

Earlier Sunday, Israel’s prime minister, Benjamin Netanyahu, told a meeting of his Likud Party ministers that no agreement had been reached with Mr. Ban and suggested that he was keeping his options open.

“I told the United Nations secretary general that an investigation of the facts has to be carried out responsibly and objectively,” Mr. Netanyahu said, according to an official who was in the room. “I am looking into other possibilities.”

Even after Mr. Oren’s comments, the official, who spoke on condition of anonymity because he was not authorized to discuss the matter publicly, insisted that Israel’s response to Mr. Ban had not been completed, and that the prime minister wanted to “decide things calmly, and not under the pressure of events.”

The government was also discussing the possibility of foreign participation in an Israeli investigation. Foreign Minister Avigdor Lieberman said he would not be opposed to including a foreign observer or observers in an Israeli-led inquiry, according to his media adviser, Tzachi Moshe.

“He thinks we have nothing to hide,” Mr. Moshe said.

In a statement adopted unanimously last week, the United Nations Security Council called for a prompt, credible and impartial investigation into the raid. Israel is also under intense pressure to lift or significantly ease the blockade of the Hamas-run Palestinian enclave.

Mr. Ban proposed a panel that would include representatives from Turkey, Israel and two or three other countries, diplomats have said. It has been suggested that Sir Geoffrey Palmer, a former prime minister of New Zealand, would lead the panel. Sir Geoffrey is New Zealand’s commissioner to the International Whaling Commission and an expert on maritime law.

Israel has balked at the notion of an international investigation, saying that it is being singled out for special treatment, and that it carries out its own investigations of such military operations. Still, faced with international fury, Israel appears to be trying to show some flexibility, and some ministers have floated ideas for changing the blockade policy.

Mr. Netanyahu argues that the naval blockade is essential to prevent the smuggling of weapons into Gaza by Hamas, which is sworn to Israel’s destruction.

But, he said Sunday: “We have no desire to make things difficult for the civilian population in Gaza. We would like for goods that are neither war matériel nor contraband to enter Gaza.”

Mr. Lieberman has suggested opening the land crossings to Gaza in return for regular Red Cross visits to Staff Sgt. Gilad Shalit, the Israeli soldier captured by Hamas and other militant groups in a cross-border raid in 2006.

Similarly, ideas have been raised for some kind of international mechanism for the inspections of boats.

“We are not indifferent to the criticism,” Isaac Herzog, a government minister from the Labor Party, said Sunday in a telephone interview. “Out of this crisis may stem a new situation, a package.”

At the start of the weekly cabinet meeting on Sunday, Mr. Netanyahu said Israel had information that the “dozens of thugs” armed with iron bars, clubs and knives who clashed with Israeli soldiers on the Turkish ship were a distinct group not associated with the hundreds of other passengers on board.

He said the group “boarded the boat separately, in a different city, organized separately, equipped itself separately and went on deck under different procedures.”

Huwaida Arraf, a leader of the Free Gaza Movement, which organized the flotilla, called Mr. Netanyahu’s assertions “another pack of lies,” The Associated Press reported. She said that all the passengers were screened for weapons, and that the group’s partners in the mission had agreed not to bring weapons on board.