US President Donald Trump has vowed to provide Egypt with firm backing and cooperation in the fight against terrorism, making the pledge to Egyptian President Abdel-Fattah El-Sisi, who is visiting Washington for the first meeting between presidents of the two countries in eight years.

Trump gave El-Sisi a warm welcome at the Oval Office, lavishing him with praise and moving to mend relations strained under the administration of his predecessor Barack Obama.

"I just want to let everybody know, in case there was any doubt, that we are very much behind President El-Sisi. He’s done a fantastic job in a very difficult situation. We are very much behind Egypt and the people of Egypt," Trump said in an Oval Office meeting with the Egyptian president.

The trip is El-Sisi's first official visit since he became president 2014. The last time an Egyptian leader visited the White House was in August 2009 when Hosni Mubarak met with Obama in the Oval Office.

"You have a great friend and ally in the United States and in me," Trump told El-Sisi, as quoted in a joint statement published by the White House.

Obama suspended military aid for almost two years following the 2013 ouster of Islamist president Mohamed Morsi, citing US concerns over the country's progress toward democracy. The freeze, which was ended in mid-2015, with new conditions imposed, has strained ties between the two long-time allies.

Trump and El-Sisi, meanwhile, have found common ground with their hard line on extremism.

During the Monday meeting, El-Sisi expressed his appreciation for Trump in “standing strong in the counterterrorism field to counter this evil ideology."

"You will find Egypt and myself always beside you in this, in bringing about an effective strategy in the counterterrorism," El-Sisi told Trump.

Egypt, which has long been one of Washington's closest allies, has been receiving $1.3 billion in US military aid yearly since signing a peace treaty with Israel in 1979, with the 2016 aid package including an additional $150 million in economic assistance.

Trump and El-Sisi already demonstrated a certain rapport before the visit. The leaders have exchanged phone calls in recent months, with El-Sisi being the first foreign leader to congratulate Trump on his election victory.

Trump said there was "good chemistry" when the two leaders met on the sidelines of the UN General Assembly in New York in September during Trump's campaign.

On Tuesday, El-Sisi is due to meet with US Secretary of State Rex Tillerson and Jordan's King Abdullah II in Washington in the fourth day of his visit.

The Egyptian leader will also hold talks with a number of US officials, representatives and senators, including General Herbert Raymond McMaster, Trump's national security adviser and US House of Representatives Speaker Paul Ryan.

He will also sit with: Devin Nunes, the head of the House of Representatives intelligence committee; Ed Royce, the Republican head of the House of Representatives Foreign Affairs Committee; and Senate Majority Leader Mitch McConnell.