As the US, Russia and the UN are struggling to bring parties in the Syrian armed conflict together for peace talks, some trust-building gestures, including prisoner exchange and a possible localized ceasefire are being negotiated.

The possibility of such moves, as well as providing humanitarian assistance to some parts of Syria, were discussed in Paris by US Secretary of State John Kerry, his Russian counterpart Sergey Lavrov and UN’s special envoy to Syria Lakhdar Brahimi.

Initiating measures toward deescalating the Syrian conflict would send a positive message and pave the way towards a fruitful peace conference, which is to be held later this month in Switzerland, both Kerry and Lavrov said at a media conference.

Prisoner exchange may be a simpler goal to achieve. Armed opposition forces are preparing lists of Syrian army soldiers and officials in their captivity, Kerry said. A similar preparation is underway in Damascus.

Achieving a total ceasefire would probably be unrealistic under the circumstances, but both US and Russia are suggesting a localized ceasefire, which would serve as a test for the readiness of both sides to curb violence.

"We talked today about the possibility of trying to encourage a ceasefire. Maybe a localized ceasefire in Aleppo," Kerry said.

Syria’s largest city Aleppo has been a scene of intensive fighting in the past few weeks.

A third important step would be providing humanitarian access to Syrian regions most affected by the violence, particularly the Damasucs suburbs of Ghouta. Foreign Minister Lavrov is negotiating such a move with Damascus, Kerry said.

Humanitarian access however would be difficult to provide, Lavrov stressed. Syrian militants are targeting foreigners, including aid workers, and have killed at least 32 members of various relief organizations trying to help Syrians, he said.

Iran invited to Switzerland

Another important issue discussed by the three negotiators deals with Iran’s participation in the conference. According to Brahimi, an invitation to the Swiss town of Montreux, where the gathering is to take place, has been sent to Tehran.

“Iran participation or not participation is not a matter of ideology, it is a matter of common sense,” the envoy said.

Kerry said that the US supports Iran’s participation in the conference, but insists that Tehran endorses the peace roadmap agreed to during the previous Syria peace conference in Geneva.

Iranian presence at the conference has been a matter of heated debate. A key ally of the Syrian government, Iran, was not welcomed in Montreux by some supporters of the armed opposition, including Saudi Arabia.

Kerry previously said Iran could contribute “on the sidelines” of the conference, a notion which was refused in Tehran, saying it undermined its dignity.

The Iranian foreign minister will visit Moscow, along with his Syrian counterpart, on Thursday.

Saudi Arabia’s participation in the conference is no less relevant than that of Iran, Lavrov said.

“We hope that in the end the UN Secretary General will invite everyone, who has an impact on the real development of the situation,” he said.

The meeting in Paris was apparently less tense than some previous meetings between Lavrov and Kerry, with the two confirming that Russia and the US are in full agreement on most issues. Apart from serious diplomatic exchanges, the two diplomats had some fun with an exchange of small presents.

PHOTO: Kerry presented Lavrov with potato from Idaho before beginning of talks in Paris: via @mfa_russia#idahopotatopic.twitter.com/vBgCfduVpb — RT (@RT_com) January 13, 2014

PHOTO: #Russia presents @statedeptspox with a typical Russian fur hat after Kerry gave Lavrov potatoes from Idaho pic.twitter.com/gWkq8QZmea — RT (@RT_com) January 13, 2014

Kerry presented Lavrov with two potatoes – a reference to an earlier telephone conversation they had had. The Russian delegation responded with a ushanka hat, an iconic relic of the Soviet era, complete with a red star, but colored cartoonish pink.