Egypt’s president on Monday hardened his stance against Ethiopia and its construction of a Nile dam, warning that “all options are open” in dealing with the project that threatens to leave Egypt with a dangerous water shortage.

Speaking in a live televised speech before hundreds of supporters, Mohammed Morsi said Egypt is not calling for war, but it is willing to confront any threats to its water security.

“If it loses one drop, our blood is the alternative,” he said to a raucous crowd of largely Islamist supporters that erupted into a standing ovation.

Ethiopia’s $4.2 billion hydroelectric dam, which would be Africa’s largest, challenges a colonial-era agreement that had given Egypt and Sudan the lion’s share of rights to Nile water. Experts estimate that Egypt could lose as much as 20 percent of its Nile water in the three to five years needed for Ethiopia to fill a massive reservoir.

“If Egypt is the Nile’s gift, then the Nile is a gift to Egypt,” Morsi said in his opening remarks.

The president’s speech reflected the importance of the Nile River to Egypt. It provides almost all of the fresh water to a country that is otherwise largely parched desert. As much as 85 percent of the Nile’s water comes from Ethiopia.

“We are not calling for war, but we will not allow, at all, threats against our water security,” Morsi said before adding, “all options are open.”

Morsi appeared to be using concern about Ethiopia’s megaproject to whip up nationalistic fervor ahead of protests planned against him later this month.

In the conference hall where Morsi delivered his speech, some of his supporters chanted slogans against Israel and accused it of colluding with Ethiopia to harm Egypt. Blaming Israel for Egypt’s problems is common here. Israel denied any connection to the construction of the dam.

Morsi said he would be willing to approach opposition groups in order to unite Egyptians around a common position with regard to the dam. This came after two prominent opposition parties declined an invitation to meet Morsi last week, citing a lack of transparency in dealing with national issues and a failure to listen to them.

“The great Nile is that which all our lives are connected to. The lives of the Egyptians are connected around it … as one great people,” Morsi told the crowd.

Shifting his tone later in the speech, Morsi said that Egypt considers Ethiopia a “friend” and noted he has visited the country twice since taking office. He said his administration is in continuous dialogue with Ethiopia and Sudan to discuss water rights.

Earlier in the day, angry Egyptian lawmakers accused Morsi’s premier of doing nothing to prevent Ethiopia from building the dam. Prime Minister Hesham Kandil had just finished addressing parliament about how the government planned to work diplomatically, legally and technically with Ethiopia over the dam when the session heated up.

Kandil called the dam’s construction an “act of defiance,” but then hurriedly left the chamber despite calls for clarification over how to handle the situation if Ethiopia rejects overtures.

“Egypt will turn to a graveyard” if the dam is completed, Egyptian lawmaker Khaled Ouda, a geologist, shouted to parliament. “The prime minister didn’t provide anything.”

Abdullah Badr, who leads the ultraconservative Islamist Salafi caucus in parliament, held up a blank notebook after Kandil’s speech and said: “I have been taking notes and the page for solutions is blank.”

“Where are the studies? Where are the solutions? This is about water security and there are enemies outside and inside — what is the role of the government and what did it do?” he said.

The crisis plays into a wider feeling of malaise in Egypt.

A diverse spectrum of the population is growing increasingly impatient with Morsi’s handling of the country’s instability, including a security breakdown and a struggling economy, more than two years after an uprising toppled longtime President Hosni Mubarak.

Opposition activists are hoping to harness the frustration of Egyptians into mass protests planned on the anniversary of Morsi’s taking office June 30.

Suggestions last week by some political leaders to aid rebels against the Ethiopian government or even sabotage the dam itself also heightened concerns in Egypt. Ethiopia has demanded an official explanation.

Egypt faces the prospect of its current water shortage worsening when the Grand Ethiopian Renaissance Dam is completed.

The crisis started last month when Ethiopia diverted the flow of the Blue Nile, one of the Nile’s sources, to make way for the dam — before a 10-member panel of experts from Egypt, Sudan, Ethiopia and other countries released a study on the dam’s impact. The move took the Egyptian government by surprise.

Ethiopia’s unilateral action appeared to ignore the 10-nation Nile Basin Initiative, a regional partnership formed in 1999 that seeks to develop the river in a cooperative manner.

Egypt complained that the 10-member panel did not give concrete answers to the impact of the dam, because Ethiopia failed to provide enough updated data to the panel. Ethiopia said the report assured that the dam will not harm Egypt. It was not possible to obtain a copy of the report to independently examine its conclusions.