US President Barack Obama made a mistake when he insisted on the immediate resignation of Syrian leader Bashar al-Assad, US Senator Tim Kaine said.

"I think when the President said Assad must go it was probably a little bit of a mistake. He got ahead of himself when he said those words," Kaine told MSNBC.

The senator pointed out that Washington was also involved in the regime change in other Arab countries, including Iraq, Libya and Egypt.

"When the United States has tried to say who the leader of another country should be in this region, we usually have not done a very good job at it," Kaine said.

According to him, having called for Assad’s resignation Obama raised some expectations in Syria and then he did not follow through because "he realized the limits of America’s ability to change a regime."

Kaine also underscored that Russia and Syria have common interests in restoring stability in the country.

"Russian President and Syrian ally Vladimir Putin has committed to keeping the Assad regime in power, therefore maintaining his interests in the region," he said.

Having criticized Obama’s policy Kaine pointed out that Congress shared responsibility for the "chaos in the Middle East".

Kaine said that the US lacks a cohesive strategy in the Middle East. Obama’s plan in Syria has three purposes – fighting the Islamic State (ISIL) terrorist group, ousting Assad and providing relief for a humanitarian crisis. According to Kaine, the three facets do not mesh together under the current program.