The Kremlin said Thursday Russian President Vladimir Putin is too busy to attend a summit hosted by Barack Obama in the United States next week, in an inauspicious start to their new relationship.
The G8 summit at the Camp David presidential retreat was to be Putin's first foreign trip since returning to the presidency on Monday after four years as premier and the chance to forge a bond with Obama who he has only rarely met.
The Kremlin explained Putin had to skip the summit as he was too busy forming a government after his inauguration but analysts said the move appeared a warning to Washington not to expect an easy ride from Moscow.
Putin told Obama in a telephone call he "unfortunately cannot take part in the May 18-19 G8 summit as on those days the formation of the Russian government will -- evidently -- still not be completed," the Kremlin said.
"The American side received this information with understanding," it added.
It also confirmed that Putin would be represented by Prime Minister Dmitry Medvedev, who until Monday served as president for the last four years and unlike Putin has a strong rapport with Obama after meeting him several times.
Putin's visit to the United States was to come at a prickly time in ties with Washington, which is pressing ahead with a European missile shield despite Russian complaints and has also slammed Russia's treatment of protesters.
The Kremlin said that the two presidents agreed to hold a bilateral meeting at the G20 summit in mid-June that is to be hosted by Mexico in the resort of Los Cabos.
The White House earlier announced that Putin informed Obama in a telephone call he would be missing the G8 summit because of the impending government reshuffle.
"Noting his responsibilities to finalize cabinet appointments in the new Russian government, President Putin expressed his regret that he would be unable to attend the G8 Summit," the White House statement said.
Putin on Thursday made his first trip outside the Moscow region since his inauguration, pointedly travelling to the Urals to visit the Uralvagonzavod factory that makes the T-90, Russia's most modern tank.
The excuse of forming the government "is hardly convincing and the fact that Prime Minister Medevdev is going instead only enforces this impression for me," Maria Lipman of the Carnegie Moscow Centre told AFP.
She noted that the demands of forming a government did not appear to be holding back French president-elect Francois Hollande -- who only takes office on May 15 -- from attending the summit.
"Putin is showing a strong distrust towards the United States which risks not disappearing," she added.
Russian officials swiftly denied there was any snub intended, emphasising that in Russia the president has the final word on the appointment of ministers who are merely nominated by the prime minister.
"In this case there is a technical problem as it is indeed the president who takes the decision about the composition of the government," Kremlin economic adviser Arkady Dvorkovich told Moscow Echo radio.
Medvedev's presence indicates the "continuity of Russian foreign policy and that the policy of strengthening relations with our partners is to be continued," Kremlin spokeswoman Natalia Timakova was quoted as saying by the Interfax news agency.
US officials also played down the move, noting that Obama's National Security Advisor Tom Donilon spent two days in Moscow this month, where he met Putin, and did not appear to believe there were sinister motives.