PORTLAND — Maine’s three leading U.S. Senate candidates said Thursday they supported President Barack Obama’s measured statements and security response to the attack on American officials in Libya this week.

All three — a Democrat, a Republican and an independent — said it’s important to let details of the situation unfold before talking about specific U.S. responses to the attack.

Two of the three sharply rebuked Republican presidential candidate Mitt Romney for his criticism of the president’s response before the extent of the attack was clear.

Republican Charlie Summers declined to second-guess his party’s presidential nominee for speaking out too soon.

“I’m not running for president,” Summers said. “That’s up to Mitt Romney.”

On Tuesday, around the time crowds were gathering outside the U.S. Embassy in Cairo and the consulate in Benghazi, Libya, Romney criticized Obama after the embassy tried to ease the tension by issuing a statement condemning “the continuing efforts by misguided individuals to hurt the religious feelings of Muslims.” It was a reference to an anti-Islamic movie posted on YouTube that is believed to have helped fuel the violence, which killed the American ambassador and three other Americans in Benghazi.

“When our grounds are being attacked and being breached, … the first response of the United States must be outrage at the breach of the sovereignty of our nation,” Romney said. “And apology for America’s values is never the right course.”

Obama, as well as some Republicans, later criticized Romney for speaking hastily.

“Gov. Romney seems to have a tendency to shoot first and aim later,” Obama said.

Obama’s initial statements after the attack, meanwhile, condemned the act and promised a response. “We will not waver in our commitment to see that justice is done for this terrible act,” he said. “And make no mistake, justice will be done.”

Summers and his rivals said Obama correctly promised a strong response and took needed security steps.

“I was very pleased to see President Obama send 50 Marines to bolster security forces” at the embassy in Libya, said Summers, who is a commander in the Navy Reserve.

He said the U.S. must act but it needs to have more facts. “What I would like to see is the next two or three days unfold.”

Former Gov. Angus King, an independent, said there are too many questions about what happened and who was behind the attack to issue blame or focus a strong national response. It’s important that the president take strong action but not overreact, he said.

“There are times you want a president who is cool under pressure, and this is one of those times,” King said.

King, who has endorsed Obama, said Romney reacted prematurely. “It wasn’t very mpressive, in my view, in terms of what you want in a commander-in-chief.”

Democrat Cynthia Dill praised the president’s response of boosting security and waiting for the facts to emerge. “We need to understand more,” she said.

Dill also criticized Romney. “I think his reaction was a knee-jerk reaction and … not at all an indication of leadership.”