U.S. President Donald Trump praised his Egyptian counterpart, Abdel Fattah al-Sissi, as a "great president" on Tuesday, even as a bipartisan group of U.S. lawmakers raised concerns about Sissi's record on human rights, efforts to keep him in office for many years and planned Russian arms purchases.

Egypt's parliament has proposed constitutional reforms aimed at allowing Sissi to remain in power until 2034, which senior U.S. lawmakers and advocacy groups have criticized, along with Egypt's repression of human rights.

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Asked if he backed the efforts to allow Sissi to potentially stay in power for 15 more years, Trump told reporters: "I think he's doing a great job. I don't know about the effort, I can just tell you he is doing a great job ... great president."

Sissi is a former general who came to power after the military overthrew Islamist President Mohammed Morsi in 2013 following mass protests against his rule. Sissi was elected the following year.

He has since overseen a sweeping crackdown on both Islamist and liberal opposition. Activists consider it the worst repression in Egypt's modern history.

Trump, who referred to Sissi as "my friend," made no mention of human rights as the two spoke to reporters.

In a later statement stressing Trump's commitment to Egypt, the White House mentioned the issue in its fifth bullet point, saying: "The United States encourages the Egyptian government to preserve space for civil society and to protect human rights."

Praising relationship with Egypt

Egypt, the Arab world's most populous nation, is of strategic importance to the United States because of its peace treaty with Israel and control of the Suez Canal, a vital waterway for global commerce as well as the U.S. military. The U.S. Congress has set aside $1.4 billion in aid to Egypt in recent years.

While there continues to be support for such aid, U.S. lawmakers have voiced deep concerns about Egypt's reported signing of a $2 billion deal with Russia to buy more than 20 Sukhoi SU-35 fighter jets and weapons for the aircraft.

Trump did not answer a question about Egypt's planned Russian arms purchase, which could expose the country to U.S. sanctions. He said "a lot of progress has been made ... in terms of terrorism and other things with Egypt."

"We've never had a better relationship, Egypt and the United States, than we do right now," Trump added as the two men spoke to reporters before meeting in the White House Oval Office.

"All the credit goes to you, Mister President," Sissi responded through an interpreter. "Thank you very much for your support on all fronts."

In a letter released on Monday, leading senators said Egypt had "unjustly detained" more than a dozen Americans, and called for their release. They also raised "serious concerns about the erosion of political and human rights."

The letter to State Secretary Mike Pompeo was signed by the influential Senate Foreign Relations Committee's Republican chairman, Jim Risch, the panel's senior Democrat, Bob Menendez, and 15 other senators.

During a congressional hearing, Patrick Leahy, the Senate Appropriations Committee's top Democrat, asked Pompeo to explain Trump's praise for authoritarian leaders.

"Maybe you can explain why a dictator like Egypt's President al-Sissi is feted at the White House, Russia's President (Vladimir) Putin, North Korea's Kim Jong Un and Turkey's President (Recep Tayyip) Erdogan are praised as strong leaders and the Saudi Crown Prince (Mohammed bin Salman) is treated as an indispensable friend and ally," he said.

Pompeo disputed that the Trump administration was treading lightly on human rights and he praised Egypt's actions in support of Israel. "We have not been remotely bashful," he said.

The Egyptian embassy was not immediately available for comment.

The White House said in a statement that Trump and Sissi discussed water issues. "These complex issues must be addressed through negotiations and with respect for international best practices," the statement said.

The statement did not refer to a specific water issue, but Egypt has criticized a dam Ethiopia is building on the River Nile, saying it could restrict waters coming from Ethiopia's highlands, through the deserts of Sudan, to Egyptian fields and reservoirs.