Russian President Vladimir Putin will not attend the Group of Eight (G8) summit to be hosted by U.S. President Barack Obama on May 18-19, the White House said in a statement on Wednesday.

In a phone call between the two presidents earlier in the day, the Russian leader, who took office on Monday, excused himself on his "responsibilities" to finalize the cabinet appointments, the White House added.

Instead, Russian Prime Minister Dmitry Medvedev will attend the summit to be held in Camp David in Maryland, said the White House, adding that Obama and Putin agreed to meet on the margins of the G20 summit in late June in Mexico.

Obama and Putin were satisfied with the "concrete achievements" of the last three years and vowed to enhance bilateral cooperation on the "basis of mutual strategic interests", said the White House.

The two leaders reiterated their interest in the "sustained high-level dialogue" that has characterized the re-set of relations, said the White House, citing the "substantial progress" on issues like nuclear security and non-proliferation, Afghanistan, the WTO, and trade ties.

Putin originally planned to attend the summit. His decision to skip the event casts a shadow over the future of U.S.-Russia relations, as Putin, who has often been critical of Washington, started his third term as Russian President.

Despite the progress cited by the two leaders, Washington and Moscow remain at loggerheads over a number of issues, including the U.S. missile defense system in Europe. Last Week, Russia said talks with the United States on the issue of missile defense system were deadlocked but there were still chances for agreement.

(Xinhua News Agency May 10, 2012)