U.S. President Barack Obama has concluded his two-day visit to Prague. The president returns to Washington with a signed nuclear arms reduction treaty with Russia and the task of persuading the U.S. Senate to approve it.
President Obama met with Czech President Vaclav Klaus Friday before boarding Air Force One for the trip back home.
While in Prague Thursday, Mr. Obama and Russian President Dmitri Medvedev signed the new START treaty. The successor to the 1991 START-One accord calls for the United States and Russia to cut their stockpiles of nuclear weapons to their lowest level since the 1960s. It also contains new procedures to allow each country to make sure the other is doing so.
"Today is an important milestone for nuclear security and nonproliferation and for US-Russia relations," he said.
Presidents Obama and Medvedev both say those relations have grown stronger and more mature during the year of tough negotiations that led to the treaty.
The two leaders say they have made great progress in their talks about developing sanctions against Iran for its refusal to stop enriching uranium.
Russia has opposed some past efforts to sanction Tehran, but Mr. Medvedev said Thursday he agrees with the need for sanctions, under certain conditions.
"Smart sanctions should be able to motivate certain parties to behave properly, and I am confident that our teams that will be engaged in consultations will continue discussing this issue," he said.
The next challenge for Mr. Obama is to get the U.S. Senate to ratify the new START treaty. Doing so will require 67 votes, and the president's Democratic Party controls only 59.
Despite the bitter partisanship that marked the recent health care debate on Capitol Hill, similar treaties have easily been approved in the past.
Many opposition Republicans are expected to vote for the treaty, although some are reserving judgment for now. Some Republicans have questions about whether the treaty is verifiable and whether a smaller U.S. nuclear arsenal will protect against attempts by Iran, North Korea or the al-Qaida terror group to acquire nuclear weapons.
Next week, President Obama will host a meeting of more than 40 heads of state on preventing nuclear terrorism and the further spread of nuclear weapons. Israeli Prime Minister Benjamin Netanyahu, meanwhile, has canceled plans to attend, and will send the head of Israel's atomic energy agency instead.