U.S. President Barack Obama defended his government’s handling of the conflicts in the Gaza Strip and Ukraine Friday even as fighting in both regions continues, despite American diplomacy. At a White House press conference in Washington, Obama hoped to discuss his plans to boost employment across the country. Instead, the president found himself answering questions on failing U.S. diplomatic efforts to bring about a cease-fire in Gaza and to check Moscow’s engagement with Kiev.

On the one hand, a territorially aggressive Russia is building its troop strength along its border with Ukraine, according to a report by the Voice of America. On the other hand, a U.S.-backed cease-fire in Gaza broke down an estimated 90 minutes after it became effective Friday.

“I think it’s going to be very hard to put a cease-fire back together again if Israelis and the international community can’t feel confident that Hamas can follow through on a cease-fire commitment,” Obama said with respect to the Gaza conflict.

When the president was asked whether he had lost his influence in the world, Obama responded that U.S. diplomatic efforts will take time, while pointing to what he said was progress in getting Russia to resolve the Ukraine conflict.

This week, the European Union joined the U.S. in imposing tougher sanctions on key Russian sectors, which the American administration had previously threatened to do. Nonetheless, Obama said there were limits to what the U.S. could do to prevent Russian interference in Ukraine.

“What we’ve done is imposed sufficient costs on Russia that, objectively speaking, they should -- President [Vladimir] Putin should -- want to resolve this diplomatically, get these sanctions lifted, get their economy growing again, and have good relations with Ukraine; but, sometimes people don't act rationally,” Obama said.

Obama told reporters he called Putin Friday and reiterated his concerns over Russia’s increasing support for separatists in Ukraine. He added that he told the Russian president he would prefer a diplomatic solution to the conflict, as the two sides agreed to keep open their channels of communication.