Foreign ministers of the Group of Eight (G8) major economies will meet this week in Washington to tackle pressing regional and global security issues such as Syria, Iran and North Korea.
US Secretary of State Hillary Clinton's expected talks with her Russian counterpart Sergei Lavrov on the margins of the G8 meetings on Wednesday and Thursday could prove especially important as Russia plays a key role on all three issues.
State Department spokeswoman Victoria Nuland did not confirm the meeting with Lavrov, but said Clinton would have four bilateral ministerial meetings during the G8 talks as the violence in Syria continued unabated.
"I'm sure that Syria will be a subject of discussion here too," Nuland said after she and other US officials said they saw no signs that Syrian President Bashar al-Assad will implement a UN-brokered ceasefire he has agreed to.
The G8 comprises not just the United States and Russia but also Britain, Canada, France, Germany, Italy, and Japan.
Like the other G8 capitals, Moscow has backed the ceasefire plan presented by Annan, the United Nations and Arab League envoy, but it puts far more weight on the Syrian opposition to stop the violence and has vetoed UN resolutions condemning Assad.
Syria is a traditional Russian military ally.
Under the peace plan, Syria's armed forces are supposed to withdraw from protest centres on Tuesday, with a complete end to fighting set for 48 hours later.
But the truce appeared in jeopardy after Damascus said Sunday it would only meet its side of the bargain if rebels first handed over written guarantees to stop fighting, a demand rejected by rebel army chief Colonel Riyadh al-Asaad.
With events building to a climax, "Syria is going to take up a lot of air time," particularly in the bilateral meetings, according to Bruce Jones, a Brookings Institution analyst.
State Department officials also told reporters that Iran's nuclear ambitions will come up.
The United States, Russia, China, Britain, France and Germany are to meet with Iran in Istanbul on April 14, after Clinton recently warned the window for ending the atomic showdown peacefully will "not remain open forever."
The first such global talks for more than a year are set against the backdrop of Iran's failure to allay Western suspicions that its uranium enrichment program masks a drive to build atomic weapons.
Tehran insists its program is entirely peaceful.
The G8 foreign ministers will also tackle concerns over North Korea's planned launch of a rocket which Pyongyang says is aimed at putting a satellite into orbit but much of the rest of the world fears is a disguised missile test.
The launch is expected between April 12-16.
G8 members the United States, Russia and Japan take part in the troubled six-party nuclear disarmament talks which also involve South Korea, North Korea and China.
The planned rocket launch has undercut a recent deal in which North Korea agreed to a partial suspension of its nuclear activities in return for massive food aid.
In Tokyo, Japanese Foreign Minister Koichiro Gemba said he would press for the G8 foreign ministers to speak out on North Korea.
"This meeting will take place right before or during the period of the missile launch announced by North Korea. I would like to cooperate closely with each G8 country to demonstrate the strong resolve of the G8 toward urging North Korea to exercise self-restraint," Gemba told reporters.