Obama vows to 'scour' US law to find possibilities for legal, executive action

President Obama said Wednesday he will “scour over” U.S. laws and regulations to see what authority he has to continue issuing executive orders but argued he has never had a “green light” to violate the Constitution or White House powers.

“I am bound by the Constitution and the separation of powers,” Obama said during a press conference at the State Department. “Congress has the power of the purse.”

The president addressed a wide-range of questions on domestic and foreign policy, including the United States’ border immigration crisis and the conflicts in Israel and Ukraine.

He avoided directly answering a question on whether he intends to expand a 2012 executive memo on immigration that would purportedly provide work permits for as many as five million illegal immigrants.

“We’ve got a broken system. It’s under-resourced,” the president responded amid speculation he will take executive action on the border issue while Congress is on August break.

Obama has asked Congress for $3.7 billion to help at the southern U.S. border, where tens of thousands of mostly unaccompanied Central Americans youths have crossed the border illegally in recent months.

He said long-term stability in Israel and the Gaza Strip will come slowly and require leaders in the region to take political risks for the sake of peace and prosperity.

The president added the short-term U.S. goal for Gaza is for a temporary cease-fire between Israel and Hamas to continue without being violated before it expiresFriday.

He also maintained that Israel has the right to defend itself from rocket attacks and terrorist tunnels into its territory by the militant group Hamas.

Obama expressed sympathy for the hundreds of innocent victims in the roughly four weeks of fighting and for Palestinian Authority President Mahmoud Abbas, whose efforts to negotiate peace with Israel has so far failed. However he said he has “no sympathy for Hamas.”

The president said the sanctions imposed against Russia by the U.S. and Europe over its actions in Ukraine are straining the Russian economy, which has "ground to a halt."

He also said that if Russia invades eastern Ukraine, it would pose a whole different set of questions for the U.S.

Western officials earlier Wednesday warned that a Russian military buildup on Ukraine's border could herald a major incursion to protect the pro-Moscow separatists fighting Ukrainian forces.

Obama was asked about the impact of U.S. sanctions on the same day of reports that Russia plans to move to ban agricultural imports from the U.S.

The president also expressed caution about the possibility of sending experimental drugs to Africa to help stop the deadly Ebola virus outbreak, which has killed an estimated 932 people in West Africa.

“We got to let science guide us. All of the information is not in,” he said, while express confidence that the virus will be controlled.

Obama made his comments on the third and final day of the U.S.-Africa Leaders Summit in Washington, D.C.

He began the roughly 45-minute event restating that the United States and the heads of state and government from more than 50 African countries agreed to work together on the major problems of health care, security and government corruption, which are stunting economic progress on the continent.

“The entire world has a stake in peacekeeping in Africa,” Obama said. “Africa will always have a strong partner in the United States.”

He also said that such improvements will help stop terrorism in that region of the world.

The conference was aimed at shifting U.S. relations with Africa away from humanitarian aid and toward more equal economic partnerships.

Obama announced $33 billion in commitments mostly from the private sector to invest in Africa and help create jobs in the U.S.

The Associated Press contributed to this report.